In Salt Lake City a couple of times a year, there is a pretty big show with all of the local dealers, and all of them have manufacturers reps there for the various brands they sell. At that one you get to see and compare things with only a little walking.
I haven't found the same thing in Las Vegas yet - just individual dealer "shows" at the various casinos/arenas. They have manufaturer reps, but you have to go from place to place to do any comparisons.