I have sailed E Class in suite and non suite...I was just fine in the non suite. The Retreat Lounge was a waste to me, it reminded of a Dr's waiting room. The pool in the Retreat area was nice for sure, along with the service, that said we spent a lot of time outside of the Retreat areas on the cruise where we were in a Sky Suite...
We met a lot of nice people around the plunge pools, and had good bar service there, and the Sunset Bar is one of my favorite bars on any ship.