avoided them due to this thread
Saw them for the first time on IAH-YYC today. The FA said they were testing them, and I mentioned to the FA that they were not getting good reviews. Person next to me got them, and they did not look too good.
Small, no cheese, some onions. He put a ton of mustard and ketchup, so that may say something about their taste.
I did not love the nuclear melted cheeseburger with cheese welded to the plate, but I would take that over the sliders all day.