I have zero desire to cruise on the Oasis. Way too big for me. It does have a lot going on, but frankly I am so uber-busy in my daily life when we cruise we just want to RELAX! I feel busy enough on the Magic/Wonder.
I also agree with a PP about no Promenade deck! One of my very favorite things to do on any cruise ship is to walk that deck, and also to find a comfy lounge chair on that deck, curl up with a book, and watch the ocean go by. Soooo relaxing. I also really love Quiet Cove pool- a drink in my hand, an uncrowded pool, great tunes playing. On Oasis I can't imagine how you would ever, ever get a pool chair. The pools are not that much exponentially bigger, to handle an additional 3000-4000 people. Admittedly, only a fraction of those would want to use the pool, but what if it's just 10% more? That's 300+ more people. No thanks, just not my thing.