Overall rock solid. I had the i7+ prior and it was excellent as well. The s9 is more noisy, not due to the vacuum fan but more so the design change. Customer service is excellent, they ultimately sent a replacement robot due to the front sensor stopped working. I think there were some initial production issues and bugs that are being sorted out as with almost any major product launch. With software updates and some tweaks it should be the best on the market especially with the no go zones. When you pair this with the m6 (which I did) it's truly amazing.