I've only been to the Amazon Fresh in my neighborhood, haven't been to other locations, here is what my experience was like:

They resisted implementing self checkout for years before eventually folding. No digital wallets though, you have to either use plastic or link it to your Amazon account.

The whole dash cart system was a solution in search of a problem IMO. I'm already able to check out about as efficiently as possible. Frontloading the scanning time isn't really an amazing improvement. The store was never crowded enough for it to matter.

My biggest problem with the store was that it was lacking random pantry staples and supplies that you would expect from your primary grocer. Several times I showed up in desperate need of something for a recipe or household task and they just wouldn't have it.

The produce was actually decent quality and competitively priced, but my alternative (the local Ralph's) I think just had some kind of curse or something on it because the produce at that specific location was a consistent level of awful observed over 5 years.

I hope they replace it with a whole foods, much better store IMO.