The only thing about the Upper Deck that I hated was being on the sides. In particular, I remember sitting in the top corner on the first base side. That was a recipe for vertigo because when everyone cheered, you can feel it.
Personally, I think every ball park should have a little discomfort factor, especially if you wanna go "retro". Put a few seats behind some pillars... or make some of the seats difficult to access. Screw comfort, this is baseball. Next thing I know, people will be whining for more retractable domes. :Shudder: