I've been on a few ocean cruises, and 1 multi-night river cruise, and I very much prefer the larger ships. With only 4 nights on the river cruise, I was sick to death of seeing the same people sitting in the same seats eating the same foods, and having literally nowhere to escape. Everyone was obligated to eat at the same time, watch the same entertainment, listen to the same music, and if you didn't like it your only other option was your room. I much prefer 4000+ people ships, with the options and space that necessarily includes.