I've experienced 45,000 ton and 109,000 ton ships, and several increments in between. Although I have a wonderful time on any ship, and can't wait to try a really small ship, I am drawn to the larger vessels. the 90,000 ton range has plenty of places to explore and still seem like a ship.
Of course I need many more cruises to provide a scientific statiscal answer. Michelle, please let me know if your experiment is privately funded. I would be most happy to "work" with you.