Roborock S8 MaxV Ultra vs iRobot Roomba Combo j9+
Quick take: The Roborock S8 MaxV Ultra runs longer per charge (180 vs 120 min).
Which one to buy
Same $800, and only the Roborock washes its own mop. Both are now discontinued: Roborock's successor is the Saros 20 Flow at $1,500, and iRobot's is the Roomba Max 775 Combo + AutoWash Dock at $800. The S8 MaxV Ultra's dock empties the bin, washes the pads in hot water and keeps them from going musty. The iRobot Roomba Combo j9+ dock self-empties but never touches the mop, so owners rinse the pad by hand after every session, which most describe as the dealbreaker at this price.
The j9+ has one genuine trick: the whole mop pad retracts to the top of the robot over carpet, so even plush rugs never get damp. Owners call it the best answer to the carpet-mopping problem, and it pairs with iRobot's dual rubber extractors, strong obstacle avoidance and quiet 65 dB running. The rest of the mop story is weak: a light damp wipe with no spinning or vibrating, a 210 ml tank that runs dry in larger rooms, camera navigation that's slower than LiDAR and needs ambient light, and some features behind a monthly subscription.
S8 MaxV Ultra owners call it the best overall robot they've owned. They praise 10000 Pa that pulls litter and fine dust out of carpet, dual rubber rollers that resist tangling, obstacle avoidance they trust unsupervised around pets, and a mop lift high enough to keep medium-pile carpet dry. The complaints are a massive dock that sent some owners rearranging furniture, a tank refill every 3-4 cleans, a thin untouched strip along baseboards, and rollers that can fling small toys rather than pick them up.
For nearly everyone the Roborock was the better $800, and the j9+ only made sense if plush rugs sit next to hard floors you want mopped daily and you're already settled in iRobot's ecosystem; with both discontinued, compare their successors instead.
Roborock S8 MaxV Ultra
For most homes, especially with pets and mixed floors, it's the more automated robot at the same price, with hot-water mop washing and obstacle avoidance owners trust; now discontinued, with the Saros 20 Flow as its successor.
iRobot Roomba Combo j9+
Only for an iRobot household with plush rugs beside hard floors, where a mop that retracts fully onto the robot matters more than a self-washing dock; now discontinued, with the Roomba Max 775 Combo + AutoWash Dock as its successor.
| Spec | Roborock S8 MaxV Ultra | iRobot Roomba Combo j9+ |
|---|---|---|
| Price | ~$800 | ~$800 |
| Type | Robot Vacuum & Mop | Robot Vacuum & Mop |
| Suction | 10000 Pa | Not disclosed |
| Battery | 180 min | 120 min |
| Navigation | LiDAR + Camera | Camera |
| Filtration | — | — |
| Cordless | Yes | Yes |
| Bagged | — | — |
| Noise | 67 dB | 65 dB |
| Dustbin | 400 ml | 400 ml |
| Water tank | 300 ml | 210 ml |
| Self-empty dock | Yes | Yes |
| Auto mop washing | Yes | No |
| Hot water washing | Yes | No |
| Obstacle avoidance | Yes | Yes |
| Carpet detection | Yes | Yes |
| Auto mop lifting | Yes | Yes |
| Multi-floor mapping | Yes | Yes |
| App control | Yes | Yes |
| Dimensions | 13.8 x 13.9 x 4.06 in | 13.7 x 13.7 x 3.4 in |
| Weight | 9.3 lbs | 8.9 lbs |
| Warranty | 1 year | 1 year |
Pros & cons
Roborock S8 MaxV Ultra
- ✓Industry-leading 10000Pa suction picks up pet hair, cereal, and fine dust with ease
- ✓Hot water mop washing keeps pads genuinely clean and odor-free
- ✓AI obstacle avoidance reliably dodges cables, shoes, and pet toys
- ✓Dual rubber brush rolls resist hair tangles better than bristle brushes
- ✓Excellent carpet detection lifts the mop pad high enough to avoid wetting carpet
- ✗Launched at $1,800 — newer flagships now undercut it on specs, so only buy it discounted
- ✗Dock is very large and requires significant floor space
- ✗Mop pressure is lighter than dedicated mopping robots
- ✗App has a steep learning curve with many nested menus
iRobot Roomba Combo j9+
- ✓Innovative retractable mop fully lifts to the top of the robot over carpet
- ✓Same excellent carpet cleaning as the j9+ with dual rubber extractors
- ✓Smart mapping learns room types and adjusts cleaning behavior automatically
- ✓P.O.O.P. guarantee covers pet waste incidents
- ✓Quieter than most competitors at 65dB
- ✗No self-wash dock — you must manually clean the mop pad
- ✗Mopping performance is mediocre compared to dedicated mop robots
- ✗Camera navigation is slower than LiDAR and needs ambient light
- ✗Expensive at around $800 without a self-washing station included
Roborock S8 MaxV Ultra vs iRobot Roomba Combo j9+: common questions
Do I have to wash the mop by hand on the Roomba Combo j9+ but not the S8 MaxV Ultra?▾
Yes. The j9+ dock only empties the bin, so owners rinse the pad after every mopping session. The S8 MaxV Ultra's dock washes the pads with hot water, which owners say prevents the mildew smell cold-water docks develop.
Is the Roomba Combo j9+'s retractable mop better than the S8 MaxV Ultra's mop lift?▾
For keeping carpet dry, yes: the j9+ lifts the pad onto the top of the robot, so plush rugs stay dry. S8 MaxV Ultra owners say its lift keeps medium-pile carpet dry, which covers most homes. For cleaning floors, the Roborock's pads do more than the j9+'s light damp wipe.
Which is better for pet hair, the S8 MaxV Ultra or the iRobot Roomba Combo j9+?▾
Both use dual rubber rollers that owners say resist tangling. The S8 MaxV Ultra adds 10000 Pa that its owners credit with pulling litter and fine dust from carpet, plus obstacle avoidance trusted around pet toys, so it edges ahead for most pet homes.