A.R.E. CX HD truck cap......

I was seriously considering the CX HD for the same reason - to get more strength for roof loading. But between the extra cost, internal framing of the shell taking up interior space, and fact that I try very much to not put heavy loads up top for stability issues, the HD wasn't for me. I went with the CX with flip open side windows, roof rack, and all the inside lights and remote locking. With the roof rack I can still put lighter things up top light cargo box, bikes, and even a 7 gal shower tank and not worry about the load factor. The rooftop tent trend just isn't something I subscribe to even for a dedicated adventure rig because I prefer to be able to set up camp and still use the vehicle to get to a trailhead or run to town for whatever reason. We have a Sylvan GO trailer and a conventional tent for shelter purposes.

The HD model seems more suited to commercial use or the rooftop tent set up but I wouldn't recommend it outside of those two cases. Even the sales guy at the ARE dealer quizzed me about the real life use of the set up and if I really wanted/needed the HD capacity.