I'm in the process of replacing mine. I was 'overloaded' with information trying to decide which way to go. Then the plumber suggested to me to look at a new Kohler that has a fast flush (3" tank outlet) and one he was impressed with. So I said yes to get that one.
A week later found it was so popular that it would be a two month backorder, and if I wanted to pick something else. I said "no", I didn't want 'second best'. So we kept the order, and it has taken so long to finish the shower installation, that the toilet has been here for a week now, and it will be about another 3 weeks for the painter to finish after which the toilet can be placed on the new spot.
It's a Kohler Cimarron K-3497 (two-piece), if you want to know that.