Roborock S8 MaxV Ultra vs. Roomba Combo j9+: Which is the Best Robot?

If you are prepared to spend over $1,000 on a robot vacuum and mop, you aren’t just buying a cleaning device—you are buying time. You want a machine that you never have to touch.

In 2026, two models sit at the top of the food chain:

1. The Roborock S8 MaxV Ultra: A technological marvel with a “FlexiArm” that extends into corners and a dock that does literally everything (even washes the mop).
2. The iRobot Roomba Combo j9+: The American heavyweight that promises the best carpet cleaning in the industry and a mop that physically lifts out of the way to keep rugs dry.

But here is the critical difference most reviews miss: One of these robots washes its own mop, and the other one doesn’t.

In this robot vacuum comparison, we break down the maintenance, the mopping tech, and the “set it and forget it” factor to help you decide.

Which Robot Should You Buy?

• Buy the [Roborock S8 MaxV Ultra] if: You have mostly hard floors and want a truly “0% effort” experience. Its dock washes and dries the mop pads automatically, so you never have to touch a dirty rag. It also navigates much faster in the dark thanks to LiDAR.
• Buy the [Roomba Combo j9+] if: You have thick carpets or are terrified of wet rugs. Its “Retractable Mop Arm” lifts the wet pad completely to the top of the robot, guaranteeing your carpets never get damp. It is also the “Pet Safe” choice due to iRobot’s legendary poop-avoidance promise.

Comparison Table: Roborock S8 MaxV Ultra vs. iRobot Roomba Combo j9+

Feature	Roborock S8 MaxV Ultra	iRobot Roomba Combo j9+	Winner
Product Type	All-in-One Robot	Hybrid Robot Vacuum	—
Suction Power	10,000 Pa	Not Listed (High Airflow)	Roborock
Navigation	LiDAR + RGB Camera	Camera (vSLAM)	Roborock
Mop Tech	VibraRise® 3.0 (Sonic scrubbing)	SmartScrub (Back & Forth)	Roborock
Carpet Protection	Lifts Mop 20mm	Fully Retracts to Top	Roomba
Edge Cleaning	FlexiArm (Extends out)	Standard Side Brush	Roborock
Dock Features	Empty, Refill, Wash Mop, Dry Mop	Empty, Refill	Roborock
Pet Poop Avoidance	Good	Excellent (P.O.O.P Promise)	Roomba
Price	Check Price on Amazon	Check Price on Amazon	Roomba

Key Differences Between These Robot Vacuums

1. The “Dock” Battle (The Dealbreaker)

This is the single most important section.

• Roborock S8 MaxV Ultra: The “RockDock Ultra” is a complete car wash for your robot. Before, during, and after cleaning, the robot returns to the dock, which sprays the mop with hot water, scrubs it clean, and dries it with hot air. You only need to refill the clean water tank once a week.
• Roomba Combo j9+: The “Clean Base” refills the robot’s water tank and empties the dustbin, but it does NOT wash the mop pad.
  • The Reality: After the Roomba mops your kitchen, it sits on the dock with a dirty, wet rag attached to it. You must manually remove the pad and throw it in the washing machine. If you want a hands-off experience, this is a major downside.

2. Carpet Performance: The Retractable Arm

Roomba wins this category, hands down.

• Roomba Combo j9+: When it sees carpet, a metal arm physically swings the wet mop pad up and onto the top of the robot. It looks like a convertible car roof. This means there is zero risk of a wet mop touching your expensive white rug.
• Roborock S8 MaxV Ultra: Uses “VibraRise.” It lifts the mop cloth up by 20mm when it hits carpet. This is fine for low-pile rugs, but if you have thick, plush carpets, the damp cloth might still brush against the fibers.

3. Navigation: Lasers vs. Cameras

• Roborock (LiDAR): Uses a spinning laser turret. It maps your house in minutes, navigates perfectly in pitch-black darkness, and moves in precise, logical lines.
• Roomba (Camera): Uses a camera to “see” landmarks. It takes longer to map the house and requires lights to be on to work effectively. If you run your robot at 2 AM, the Roborock is the better choice.

4. Edge Cleaning (The FlexiArm)

• Roborock S8 MaxV Ultra: Features a robotic FlexiArm side brush that literally extends out from the body to sweep dust out of corners. It also has a mini “side mop” that spins to clean the edges of your kitchen cabinets.
• Roomba Combo j9+: Uses a standard spinning side brush. It’s effective, but it doesn’t have the “reach” of the Roborock.

What’s In The Box?

Roborock S8 MaxV Ultra Box Contents

1. S8 MaxV Robot: With built-in FlexiArm and camera.
2. RockDock® Ultra: The massive station (Washes, Dries, Empties, Refills).
3. Disposable Dust Bag: Pre-installed in dock.
4. Power Cord.
5. User Manual.
6. Note: Roborock rarely includes extra bags or pads; you usually have to buy them separately.

iRobot Roomba Combo j9+ Box Contents

1. Roomba Combo j9+ Robot.
2. Clean Base® Auto-Fill Dock: Empties bin and refills water.
3. High-Efficiency Filter: Extra included.
4. Edge-Sweeping Brush: Extra included.
5. Microfiber Mop Pad: (Reusable).
6. Dirt Disposal Bag: Extra included.
7. Power Cord.

Winner: Roomba. iRobot is generous with spare parts (extra filter, bag, and brush) right in the box.

Real User Complaints: What Do People Hate?

Common Complaints: Roborock S8 MaxV Ultra

• “The App is Overwhelming.” The Roborock app has 1,000 settings. You can adjust suction power, scrub intensity, floor direction, and “pet mode.” Tech geeks love it; regular users sometimes find it confusing.
• “Maintenance Required.” While it washes the mop, the dock itself gets dirty. You need to clean the “maintenance tray” in the bottom of the dock every 2-3 weeks, or it will smell like wet dog.

Common Complaints: Roomba Combo j9+

• “I have to wash the pad myself?” Many users are shocked that a $1,000+ robot doesn’t wash its own mop. If you forget to remove the dirty pad, it can get moldy.
• “Navigation is slower.” Because it uses cameras, it bumps into furniture more often than the laser-guided Roborock. It also takes longer to finish a cleaning run.
• “Loud Operation.” The Roomba is a powerful vacuum, but that means it is loud. It sounds like a jet engine when the base station empties the dustbin.

Maintenance & Ongoing Costs

1. Dust Bags

Both docks use disposable bags. You will need to buy a pack of 6 every year.

• Cost: Roughly the same ($3–$4 per bag).

2. Mop Pads

• Roomba: You need a stack of these because you have to wash them manually.
• Roborock: You can use the same pad for months because the dock keeps it clean.

3. Cleaning Solution

• Roborock: Has a dedicated detergent tank in the dock. It automatically mixes the solution.
• Roomba: You can pour cleaning solution into the refill tank, but you have to mix it yourself.

FAQ

Is the Roborock S8 MaxV Ultra worth the higher price?

If you want hands-free mopping, yes. The ability to wash and dry its own mop pads changes the experience from “chore” to “magic.” With the Roomba, you are still doing laundry.

Does the Roomba j9+ avoid dog poop?

Yes. iRobot has the P.O.O.P. (Pet Owner Official Promise). If the J9+ runs over pet waste within the first year, they will replace the robot for free. Roborock has good avoidance, but no replacement guarantee.

Can the Roborock clean deep carpets?

It is good, but the Roomba is better. Roomba’s dual rubber brushes are widely considered the gold standard for pulling hair out of deep carpet fibers without tangling.

Final Recommendation

This choice comes down to one question: How much carpet do you have?

If your home is mostly carpet (70%+), buy the iRobot Roomba Combo j9+. The retractable arm is the only technology that guarantees your rugs stay dry, and its rubber brushes are unbeatable for deep cleaning.

If your home is mostly hard floors (wood, tile, vinyl), the Roborock S8 MaxV Ultra is the superior machine. The auto-wash dock means you never have to touch a dirty mop, and the FlexiArm cleans corners better than any other robot on the market.