Introduction
The Roborock Qrevo Curv and Qrevo Curv S5X represent two variants within Roborock's 2024 flagship range, whilst the Dreame X40 Ultra arrives as a direct competitor from one of the market's most dynamic brands. All three models feature multifunctional bases with mop washing and drying capabilities, positioning them firmly in the premium segment where complete autonomy is the priority.
The Qrevo Curv stands as Roborock's most advanced offering with dual AI cameras and enhanced navigation features. The S5X variant shares the same powerful suction but strips back some intelligent functions to hit a more accessible price point. Meanwhile, the X40 Ultra from Dreame brings its own arsenal of technology, including detergent dispensing and superior object recognition.
These aren't entry-level machines. They're designed for households demanding minimal intervention—homes with multiple floor types, pet hair challenges, or simply users who want their cleaning handled without constant supervision.
Key differences at a glance
- The Qrevo Curv delivers 240 minutes of autonomy versus 180 in the S5X and 194 in the X40 Ultra
- Only the Qrevo Curv lifts its main brush whilst mopping; the S5X cannot
- The X40 Ultra is the sole model with a liftable side brush and detergent tank
- Dual AI cameras appear in the Qrevo Curv and X40 Ultra, but not the S5X
- The X40 Ultra recognises 120 obstacles compared to 62 in the Qrevo Curv
- Only the Qrevo Curv includes a built-in voice assistant
- The X40 Ultra can automatically remove its mops at the base for vacuum-only sessions
- Battery capacity: 6,400 mAh in the Qrevo Curv and X40 Ultra, 5,200 mAh in the S5X
Power and suction
Suction power separates these models dramatically. The Roborock Qrevo Curv and S5X both deliver 18,500 Pa—a figure that places them amongst the most powerful robots available. The Dreame X40 Ultra sits at 12,000 Pa, which remains robust but noticeably lower when tackling deep-pile carpets or embedded debris.
All three employ anti-tangle brush designs. Roborock's DuoDivide system pushes hair towards the central suction channel, minimising wrap-around on the roller itself. Dreame opts for a simpler single brush configuration, though it still incorporates anti-tangle features. In practice, homes with long-haired occupants or shedding pets will benefit from either approach, though the DuoDivide has proven particularly effective in reducing maintenance frequency.
The Qrevo Curv can lift its main brush when mopping, preventing the roller from dragging dirt across wet floors. The S5X lacks this capability, which can lead to streaking if the brush hasn't been cleaned recently. The X40 Ultra matches the Curv here, adding main brush elevation to its feature set.
Side brush functionality varies too. Whilst all three extend their side brushes to sweep edges more effectively, only the X40 Ultra lifts its side brush during mopping. This prevents the brush from flicking water or creating messy streaks along skirting boards—a detail that matters during intensive mopping sessions.
Mopping
Each model uses dual rotating mops, but their implementation differs. The Qrevo Curv extends its mops to reach edges and can lift them between 10-20 mm when encountering carpets. The S5X offers the same extension but with a fixed 10 mm lift, whilst the X40 Ultra lifts to 10.5 mm and adds Roboswing—a movement that angles the mop slightly under furniture edges and low overhangs.
Mop washing happens with hot water at 60°C in both Roborock models and the Dreame. Drying uses heated air across the board, which accelerates the process and helps prevent bacterial growth. The bases also clean their own wash trays automatically, with Roborock's 2.0 system and Dreame's second-generation equivalent ensuring the cleaning station doesn't become a source of odours.
A standout feature of the X40 Ultra is its ability to automatically detach its mops at the base, allowing it to vacuum without any mopping hardware attached. This proves useful in homes where certain rooms never need mopping, or during seasons when wet cleaning isn't required. Neither Roborock model offers this.
The X40 Ultra also includes a detergent tank, dispensing cleaning solution during mop washing for enhanced results. The Qrevo Curv and S5X rely on water alone. For households dealing with sticky spills or heavy soiling, this addition can make a tangible difference in floor cleanliness.
Navigation system
Navigation hardware reveals where cost-cutting has occurred in the S5X. The Qrevo Curv sports dual AI cameras, a 3D laser sensor, LED lighting for night operation, and remote camera access via the app. It recognises 62 different obstacle types and can identify pets specifically, adjusting behaviour accordingly.
The S5X strips this back considerably. It retains LiDAR mapping but loses the AI cameras, 3D sensor, LED lighting, and remote viewing. Pet recognition disappears too. It'll still navigate competently and avoid large obstacles, but it won't adapt to specific objects or allow you to check on your home remotely.
The Dreame X40 Ultra goes furthest in this category, recognising 120 obstacle types—nearly double the Qrevo Curv. It includes dual AI cameras, 3D sensing, LED illumination, and remote camera access. Uniquely, it can detect curtains and adjust its approach to avoid tangling. For complex homes with varied furniture, cables, and pet accessories, this level of recognition reduces the need for pre-cleaning tidying.
All three use advanced AI-driven cleaning strategies—SmartPlan 2.0 in the Roborock models and CleanGenius in the X40 Ultra. These systems learn room layouts, prioritise high-traffic areas, and adjust suction or mopping intensity based on detected dirt levels.
Battery and autonomy
Battery capacity directly influences how much ground these robots can cover before returning to base. The Qrevo Curv and X40 Ultra both pack 6,400 mAh cells, whilst the S5X contains 5,200 mAh. This translates to 240 minutes of runtime for the Curv, 194 minutes for the X40 Ultra, and 180 minutes for the S5X.
For homes under 150 square metres, all three will comfortably complete a full clean without recharging. Larger properties benefit from the Curv's extended runtime, particularly when dealing with multiple floor types or intensive mopping sessions that consume more power. The S5X may require a mid-clean recharge in sprawling layouts, though it will resume automatically once topped up.
Intelligent features
Obstacle climbing varies slightly. The Qrevo Curv can tackle single-step thresholds, the S5X manages 20 mm, and the X40 Ultra handles 22 mm. In real terms, this means all three will cross most door thresholds and low carpet edges without assistance, though the X40 Ultra has a marginal advantage with taller transitions.
The Qrevo Curv includes a built-in voice assistant, allowing direct voice commands without relying on Alexa or Google Home. This can be convenient for quick instructions when your phone isn't to hand. The S5X and X40 Ultra lack this but still integrate with external voice assistants.
Multifunctional cleaning base
Base dimensions differ notably. The Roborock stations measure 450 mm in width, height, and depth—a substantial cube that requires dedicated space. The X40 Ultra's base is narrower at 340 mm wide but taller at 590.5 mm, making it better suited to tight corners but potentially problematic under low shelving.
Tank capacities favour the Dreame slightly. Its dust bag holds 3.2 litres versus 2.5 litres in the Roborock models. Clean water capacity is 4.5 litres compared to 4 litres, and dirty water sits at 4 litres versus 3 litres. These differences mean fewer refills and emptying cycles over a month of use, particularly in larger homes.
The X40 Ultra offers an optional plumbing connection kit, allowing the base to refill and drain automatically when installed near water supply lines. This isn't included as standard and requires separate purchase and installation. Neither Roborock model offers this option, even as an add-on.
Dimensions
Robot height matters when navigating under furniture. The X40 Ultra stands 97 mm tall, the S5X at 98 mm, and the Qrevo Curv at 103 mm. That 6 mm difference between the Curv and X40 Ultra can determine whether the robot accesses beneath certain sofas or bed frames. Diameter remains nearly identical across all three, ranging from 350-352 mm.
The Curv's additional height accommodates its more complex sensor array and larger battery. If your furniture clearance is tight, measuring before purchase is worthwhile—those few millimetres can be the difference between comprehensive coverage and missed zones.
Real-world usage
Large homes benefit most from the Qrevo Curv's extended 240-minute runtime and powerful 18,500 Pa suction. Properties exceeding 200 square metres, especially those with thick rugs or multiple levels, will appreciate not having to manage mid-clean recharges. The dual AI cameras and comprehensive obstacle recognition mean less pre-cleaning preparation.
Pet owners should weigh the anti-tangle brush systems and suction power. Both Roborock models excel here with their DuoDivide design and high Pa ratings. The X40 Ultra's superior object recognition (120 types) and pet detection make it particularly adept at navigating around toys, bowls, and unexpected messes.
The S5X suits those prioritising suction performance over advanced navigation. It delivers the same 18,500 Pa as the flagship Curv but sacrifices AI cameras and extended battery life. For smaller homes under 120 square metres without complex obstacle courses, it provides excellent value without the premium features you might not use.
Mopping performance is strong across the board, though the X40 Ultra's detergent tank and automatic mop removal add flexibility. Homes with mixed flooring—where some rooms need only vacuuming—benefit from the Dreame's ability to switch modes without manual intervention.
Conclusion: which to choose?
Choose the Roborock Qrevo Curv if you want maximum autonomy and the most advanced Roborock technology available. The 240-minute runtime handles expansive homes, dual AI cameras provide superior navigation, and the built-in voice assistant adds convenience. It's ideal for multi-level properties, homes with pets, and users who value remote camera access for security or monitoring.
Choose the Roborock Qrevo Curv S5X if you prioritise suction power but can live without advanced AI features. The 18,500 Pa matches the flagship model, and the multifunctional base delivers complete mop washing and drying. It suits smaller to mid-sized homes where the 180-minute battery suffices, and where obstacle layouts are straightforward enough not to require extensive object recognition.
Choose the Dreame X40 Ultra if you want the most comprehensive obstacle recognition and appreciate the flexibility of automatic mop removal. The detergent tank enhances mopping results, and the 120 recognised objects mean fewer stuck situations. It's particularly suited to homes with varied furniture, pets, and users who want minimal manual intervention. The optional plumbing kit future-proofs the installation for those willing to invest in permanent setup.
