I have to agree that the Oasis of the Seas and the Allure of the Seas definitely have a 'wow' factor, that's for sure!
We, too, have been on ships as small as 19,000 gross tons up to 220,000 gross tons and there is a huge difference between the two in the amenities that they offer. Obviously, larger ships can offer many things a smaller ship can't. But then again, smaller ships can offer a more intimate experience that the larger ships can't offer.
We've loved them all as they all have offered us something different. And that's the fun thing about cruising; there's something for everyone.
But everyone should definitely try the Oasis-class at least once just for the sheer novelty of it, if nothing else - they truly are amazing.
Then again, I think everyone should try everything at least twice to make sure they have an honest opinion of what they're truly like from their own personal experience.