Go with the coach that has the highest GVWR (the maximum fully loaded design weight of the coach). Even if the Diplomat seems to have more storage, it doesn't do you any good if you are pushing the GVWR.
Even if you are full timing, it may not make sense to fill every nook and cranny. There are stores everywhere that sell the consumables you need, there is only a very limited amount of work you can do by the roadside in case of a breakdown and spares are readily available either locally or can be ordered and delivered overnight or in just a few days.
What about things like the leveling system? The Camelots are available with air leveling - a great option. Aqua-hot heating? These are the kinds of things that add a lot to easy and comfortable usability of a coach. Washer/dryer? We have a stacked washer dryer in our Camelot. Works much better than the combo units and we don't have to play the quarters game at the local laundromats. Yes, we lost some cabinet space, but it was a trade off that was well worth it.
2006 Camelot PAQ
RR8S Chassis, Cummins ISL 400 hp
Ford Flex Toad