I think the Go stores mostly bit the dust after that reveal, but they were also mostly small convenience store operations. I actually saw one at the airport recently, that's a situation where I can see it making sense as an option.

The Fresh stores are basically a conventional grocery store, with electronic tags for every item and quirky pricing. They also have "smart carts" with built in weight sensing and multiple cameras so you can basically put open bags in, say "ready to go" then shop by scanning a UPC before placing each item in the cart. Unscanned item? Error. Weight mismatch? Probably an error but I've never tried. The carts are running what looks like a Linux-based UI with some stuff in docker, I grabbed a picture of a shutdown screen on one not too long ago.