I would agree that Apex is probably better for the Caribbean and warm climates, so that you can really take advantage of the Retreat Deck. However, we were on Apex for a cooler cruise (British Isles and Iceland), and the Retreat Lounge was awful, because that's where everyone was, and not on the Retreat Deck. It was almost always overcrowded and was often difficult to find a place to sit, let alone a comfortable place, as Jim explained. And the overcrowding was worsened by the increased number of suites on the E class ships. We're going back to S class suites now unless it's the Caribbean.