I used one in San Francisco once because I wanted to try it out. It was honestly a rather flawless experience for me and I liked it because the scan gate and minders (it was when it launched - I don't know if they kept them) kept the shoplifters out. Shoplifters are unpleasant to share a store with. Unsurprisingly, those who skip some social norms also skip other ones.

Anyway, I didn't go back after the first time because it was more like a corner store than a grocery store. Bags of chips and sandwiches in plastic boxes and so on. Overall, the modern Whole Foods is a much better experience. Guards at the entrance to keep unpleasant people out, a fairly quick check-out experience, and the ability to scan your palm instead of having to pull out a credit card or tap your watch.

About the only improvement that I would personally like is a Fast Shopper bonus where you scan something that maps you to your Amazon Prime profile and if you finish checking out fast you get access to a faster lane. The only downside is when people with large bags of things insist on using the self check-out counters and then stand there having mis-scanned items.

Speeding up check-out is a personal life improvement but realistically it would not cause me to shop more, so I understand discontinuing the store.