I want functionality. Since I am not using it as a long term seating situation, I just want it to work. With the exception of height, most toilet "comfort" is achieved by the seat, most of which will fit any brand toilet. If you live near a Home Depot, go to their plumbing section and look at the wall display they have with all the specifications of the toilets they sell. You will find that the discharge hole may be from 1-1/2" up to 2-3/8". This is a big difference. American Standard uses Fluidmaster fill-valves, which I really like. Short or long flushes can usually be adjusted with the flapper chain. Make sure the trap is fully glazed.
if you have never made a mistake, you probably haven't done much.