We have eaten at both at least twice, and will be going back to both in our coming trips. IMHO:
Shula's is steak, and they do it very well (and don't even ask me about how much the market price was for the lobster last visit). But, the atmosphere seems to be 'stuffy' compared to most other WDW area restaurants.
BlueZoo is primarily seafood, but their filet was fork tender excellent last visit, and they seem to have alot more menu choices. It is trendy, newer, etc..., and they seem to run with that atmosphere.
The service in both places is usually excellent, but a bit more 'formal' (I guess) at Shula's. And, neither one is a cheap meal!!
Go with what your preferences are (steak or seafood), but all things being equal, we would have to say BlueZoo.
Hope that helps,
Robert P