Roomba Combo j9+ vs. Roborock S8 Pro Ultra

Table of Contents

1. TL;DR Verdict

• Pick the Roomba Combo j9+ if you value bulletproof obstacle avoidance, iRobot’s “Dirt Detective” room-prioritizing logic, and a dock that empties debris (~60 days) and refills mop solution (~30 days) but don’t mind washing pads yourself.

• Pick the Roborock S8 Pro Ultra if you want the truly “set-and-forget” station that washes & dries mop pads, refills the tank, and empties dust (≈7 weeks), plus 6000Pa suction and dual vibrating mop tech—at the cost of a larger dock footprint.

2. Spec Snapshot

*Prices fluctuate—check current Amazon listings.

3. Dock Wars: Auto-Fill vs. Auto-Wash/Dry

iRobot’s Clean Base Auto-Fill Dock empties debris for ~60 days and tops off the robot’s water for ~30—dramatically reducing tank/bag chores, but you still remove and rinse the mop pad.

Roborock’s RockDock Ultra goes further: it washes and hot-air dries the mop after each run, refills water, self-empties, and even cleans its own wash plate—meaning you mostly swap a dust bag and empty a dirty-water tank occasionally.

4. Vacuuming & Mopping Performance

Roomba Combo j9+

• Dual rubber rollers excel at pet hair with minimal tangles.
• SmartScrub mode scrubs back-and-forth with pressure for sticky kitchen spills.
• Suction is strong (no published Pa number), and Dirt Detective cleans the messiest rooms first.

Roborock S8 Pro Ultra

• 6000Pa suction and a liftable dual brush + sonic mop system handle mixed floors; mop lifts on carpets to keep rugs dry.
• RTINGS notes excellent dock automation and app depth, but fine debris pickup on carpet isn’t class-leading.

5. Navigation & AI Brains

Roomba leans on PrecisionVision obstacle avoidance (with iRobot’s well-known promise to dodge pet messes) and Dirt Detective, which analyzes historical runs to prioritize dirty rooms.

Roborock uses LiDAR + Reactive 3D sensors for fast, accurate maps and solid object dodging. Digital Trends points out its fully automated pad care gives it an edge in long-term convenience.

6. Ownership Costs & Maintenance

• Roomba: You’ll buy mop pads/solution and Clean Base bags; no pad-wash means more manual upkeep.
• Roborock: Dock consumables include dust bags and water filters; pad washing reduces pad replacements but pads still need periodic swaps. RTINGS flags higher recurring costs overall.

7. Footprint & Aesthetics

Both docks are big. Roomba’s looks like a tall cabinet; Roborock’s RockDock Ultra is wider and deeper to house wash/dry components—measure before you buy.

8. Community & Review Sentiment

• Amazon ratings hover around 2.8/5 (j9+) and 4.2/5 (S8 Pro Ultra)—Roomba owners often praise navigation and reliability but complain about price and some dock quirks; Roborock buyers love the automation but mention dock size and cost.
• Independent testers (Digital Trends, RTINGS) consistently call the Roborock’s pad wash/dry a major differentiator.

9. Pros & Cons

Roomba Combo j9+ — Pros
• Auto-empty and auto-refill (rare combo)
• SmartScrub + Dirt Detective logic
• Strong pet-hair pickup, trusted support network

Cons
• No pad wash/dry—manual pad care required
• Higher MSRP than many feature-richer rivals
• Mixed user reviews about docking/water issues

Roborock S8 Pro Ultra — Pros
• Full-service dock: wash, dry, refill, empty
• 6000Pa suction, liftable dual brush & sonic mop
• Powerful app, LiDAR maps, low lag navigation

Cons
• Huge dock; recurring costs (bags/filters) add up
• Fine debris on carpets not best-in-class (per RTINGS)
• Higher price than many will stomach

10. Which One Should You Buy?

• Roomba Combo j9+ on Amazon
• Roborock S8 Pro Ultra on Amazon

FAQs