I think we're in the minority but we're not frequent cruisers (on ave once every two years). The wife and I generally liked the larger ships. The variety on them is what kind of appealed to us to RCI in the first place. We originally sailed on Navigator for our honeymoon and were thrilled. Next was on Vision and that was kind of disappointing for us. We recently sailed on Liberty and really enjoyed that. And we have been looking forward to sailing on Oasis or Allure once the hype has died down a bit.
However, apart from the novelty factor of the larger RCI ships, we actually liked the activities on our single Celebrity cruise better and are looking to sail again on X.