We've been on Crystal and Cunard, which both have two seat dining. Although I didn't like the idea of it, in reality, it didn't make any difference. We like to eat late so we just pick the late dining and if we get hungry earlier, we just have a few hot apetizers in one of the bars but usually I'm trying to stall dinner as late as possible because I'm not hungry. It's hard to be hungry on a cruise ship :) The 8pm or 8:30 for late seating is perfect.
