Great thread.
I've personally gone from a ground tent to an Eezi-Awn Globetrotter on my M101CDN. Looking at downsizing and selling the trailer/tent combo and looking at RTT's. The one HUGE thing I love about the Globetrotter tent is the ability to climb out of the tent and directly into the vestibule w/o leaving the tent. That's completely doable with the ARB Simpson III and all of the similar knockoff's but as users have noted, the set up/tear down takes more time and I'm no spring chicken any longer climbing all over the truck taking down a soft side RTT! Maggiolina now has a completely enclosed changing room that they didn't have when I went with the Globetrotter. Pros and cons to every style.
Desert camping encounters a lot of very high winds (enough to blow down a Springbar one evening!) so that's a huge consideration. Must mount to an INTI roof rack and I still want the ability to exit the tent sleeping area into an enclosed shelter. I like the durability in high winds of the hard shells over the soft tops and set up time. Even the Globetrotter with it's very heavy EeziAwn canvas flaps in the high winds a lot. I've found very, very little on the Maggiolina changing room. Quick emails with Autohome got me some info on it, but no real world feedback on any of the several boards I'm on. The changing room has pole supports so sounds like it would be similar to setting up a ground tent that then hooks onto the roof of the Maggie.
James Baroud doesn't have an exterior room option so that one is out of the running on the hard shells.
On the Maggie's the mattress size on the crank ups is only 72" and on the air strut 78". They don't make an XXL in the small model, which is all I need as a single. The Globetrotter is 78". Feedback from a friend with a 5+ year old Maggie Airlander with the gas struts is that those struts do age and need a little assistance going up now, but outside of the mattress cut outs for the struts the mattress is 78". I'm only 5' 10", but having only 2" extra seems kind of short! He also was of the opinion that the crank up style would probably be a little more sturdy in high winds due to the criss-cross structure support at each end as opposed to the struts at each corner of the Airlander.
Ah, decisions, decisions, decisions...