I don't think there's really a "bad" seat in the house... except maybe the upstairs sides... and only then b/c of the way the tables are laid out, people with their back to the rail (for the meal) would have to turn around in their seats for the show... kind of prevents the veiwing/munching/conversation factor....
The cast walk around the room during the show. A couple even come upstairs during one part.
One thing to remember, seating is ASSIGNED... so although everyone "huddles" near the entrance, there's really no need... show up just before show time, check in with the CM w/a clipboard outside, and you'll get your table. I believe there was a CM that actually "seated" us.. or directed us... it's a bit fuzzy right now...
We sat upstairs but on the back, and had a direct view of the stage.. the kids sat next to the rail and LOVED it...
I would really recommend HDDR, yes, it's "Campy" and "Cheesy", but it is fun, and it was a hit with my kids.... nice to be entertained without a "character" in sight!