When making the reservation (Priority Seating) the guy really didn't care about seating (they aren't at the parks, they aren't at the restaurants, they have no control!) BUT mentioned that I was the first one who had made a PS for that time (11:30am, their earliest seating), and that if I checked in early it would be hard to NOT get waterside.
But we checked in early, requested it, and got it. They put all the early people at the water.
All that said, we liked it better away from the water. My 4 year old wasn't trying to leap over the fence for one, and I could see better b/c closer to the door it's lighter. Ever since having Lasik done I have horrible awful rotten light-to-dark-to-light vision, it takes ages for my eyes to adjust, and for the first 5 or 10 minutes sitting in BB I had very low vision (made worse by the ding dang candles blazing streaks on my retinas). Waterside is worth doing once, but it isn't all it's cracked up to be sometimes!