you will enjoy riverside. We just there on our trip last week and thought that it is much better than the balcony.
Remember your seat location is determined by when you arrive at the checkin. (front rows get assigned first) They do have you check in 1 hour prior to showtime. We check-in 1 hour and 30 minutes prior to show time and there was a group of 10 that check-in before us, so you can check in as soon as you see someone at the desk beside the seating area.
call me crazy but I think I would prefer the riverside seating. It would make you a bit closer to the magic would it not? And you still get goodies to eat YUMMY!