Just returned from a cruise on the Oasis of the Seas. Beautiful ship and had a wonderful time. It's a great cruise for active families or anyone who wants a lot of options of things to do. Shows were wonderful - the food couldn't be better in my opinion. We had some wonderful meals and the wait staff was terrific. All of the staff are friendly, helpful and pleasant. The ship is so incredibly large that you never feel movement at all and the beds are fantastically comfortable. We were two women dressing for dinner every night and had no problem at all moving around the cabin.
Improvements needed are few: for one, the coffee is absolutely terrible and by the end of the cruise I had to start watering it down just to drink it! Also - we so enjoyed the formal dinner nights (we had two) but the dress code is not enforced and one night we sat with a couple in tee shirts and shorts! It's not like there are not other options for dining if you don't choose to dress up! That was a little disappointing for us. Also, in this day and age, charging for wireless internet is disappointing - and expensive!
For me personally, I think I would prefer a smaller, more intimate cruise experience on my next cruise. Oasis is an impressive ship - but it seems very "closed in" to me. Lots of glass enclosures but I would rather have the feeling of being outside more, not feel like I'm on the inside looking out! Pools are not that impressive and are rather small for such a big ship and passenger size - although there are many of them. The Solarium is beautiful, but again - you feel like you are inside looking out through glass.
I would love to try another cruise line at some point and will do some searching of reviews on other lines - I've only cruised on Royal Caribbean (Jewel of the Seas five years ago) and would absolutely cruise with them again and highly recommend!