Quick Verdict

iRobot Roomba j9+ and Roborock S8 Pro Ultra represent the premium tier of robot vacuums with different philosophies. iRobot pioneered the category and maintains strengths in object recognition and ecosystem trust. Roborock offers more features, better mopping, more dock automation, higher suction, at similar or lower pricing. For most buyers, Roborock delivers more capability. iRobot remains competitive for those prioritizing obstacle avoidance excellence or brand trust.

Head-to-Head Comparison

Mopping Performance

Winner: Roborock S8 Pro Ultra (decisively)

Roborock's VibraRise 2.0 uses sonic vibration mopping at 3,000 times per minute with automatic mop lifting for carpets. The dock washes and dries mops automatically. Mopping is genuinely effective, not token.

iRobot Roomba j9+ is vacuum-only. The separate Braava mop requires additional purchase and management. For combined vacuum-mop needs, Roomba provides no solution.

For households wanting both vacuuming and mopping automation, Roborock wins decisively.

Dock Automation

Winner: Roborock S8 Pro Ultra

Roborock's Ultra dock auto-empties dust, washes mops, refills water, and dries mops with hot air. The automation is comprehensive, weeks of hands-off operation.

Roomba j9+'s Clean Base auto-empties dust effectively but has no mopping support. The dock serves one function well.

For maximum automation, Roborock's dock does more.

Obstacle Avoidance

Winner: iRobot Roomba j9+

iRobot's P.O.O.P. (Pet Owner Official Promise) guarantees against pet waste spreading. The object recognition identifies and avoids hazards with industry-leading accuracy.

Roborock's obstacle avoidance is excellent but iRobot has invested more heavily in this specific challenge. The difference matters for pet-heavy households.

For obstacle avoidance confidence, particularly pet waste, iRobot leads.

Suction Power

Winner: Roborock S8 Pro Ultra

Roborock delivers 6,000 Pa suction, among the highest available. Deep cleaning on carpets is thorough.

Roomba j9+ doesn't publish Pa ratings but independent tests show lower suction. Cleaning is effective through multiple passes and brush design rather than raw suction.

For single-pass deep cleaning, Roborock's suction advantage shows.

Mapping and Navigation

Winner: Tie

Both use LiDAR navigation with multi-level mapping. Both create accurate floor plans. Both navigate efficiently with minimal missed areas.

Navigation technology has matured, premium robots from either brand perform comparably.

App and Smart Features

Winner: Tie

Both apps offer room-specific cleaning, scheduling, no-go zones, and detailed controls. Both integrate with voice assistants.

App experiences are comparable in functionality and usability.

Pricing

Winner: Roborock S8 Pro Ultra

Roborock S8 Pro Ultra: $1,400-1,600 with comprehensive dock.

iRobot Roomba j9+: $900-1,100 for vacuum-only with Clean Base. Adding Braava mop brings comparable total investment for less capability.

Roborock provides more features at similar investment.

Brand Trust

Winner: iRobot (slightly)

iRobot has decades of Roomba history. Service, parts, and support are established. The brand is proven.

Roborock is newer but has built strong reputation quickly. The brand is trustworthy but less time-tested.

For risk-averse buyers, iRobot's track record provides comfort.

When to Choose iRobot Roomba j9+

iRobot Roomba j9+ is the right choice when:

• Pet waste concern: P.O.O.P. guarantee provides confidence
• Obstacle avoidance priority: Best-in-class object recognition
• Brand trust matters: Decades of proven reliability
• Vacuum-only needed: No mopping requirement
• Existing iRobot ecosystem: Integration with other Roomba products
• Risk aversion: Established brand feels safer

When to Choose Roborock S8 Pro Ultra

Roborock S8 Pro Ultra is the right choice when:

• Mopping wanted: Effective automated mop-and-vacuum combination
• Maximum dock automation: Self-washing, drying, refilling mops
• Strongest suction needed: Deep carpet cleaning priority
• Feature maximization: Most capability for investment
• Hands-off operation: Weeks between any maintenance
• Value focus: Better features per dollar

Final Recommendation

Choose Roborock S8 Pro Ultra for the most capable robot vacuum available. The mopping performance, dock automation, and raw capability exceed iRobot at comparable pricing. For most households, the feature advantage is decisive.

Choose iRobot Roomba j9+ if pet waste avoidance is paramount or vacuum-only cleaning is sufficient. The obstacle recognition is genuinely superior, and the brand trust matters for risk-averse buyers. The product is excellent, just not as feature-rich as Roborock.

For maximum automation and capability, Roborock wins. For specific use cases (pet waste, vacuum-only), iRobot competes effectively.