I can't go any lower, it's already resting on the fenders. Plus I can barely fit a sleeping bag under it as is.
The shell/sleeping platform are great. I love being able to just climb back there and go to sleep. It's really nice. I just wish I had another foot of headroom.
Here's my take on the whole sleeping/camping/etc. thing. I don't have near the trail camping days as some people on here, but I've had a few rigs. Honestly, the camper shell has fewer drawbacks than most things out there. I've yet to see ANY camping solution that works without compromise. It's all in what you are willing to live with.
FWIW, I'm seriously thinking about another camper shell vs. doing a RTT setup on my Dodge. Each has it's plus' and minus'. Dust/dirt is a huge factor in each (I'm not experienced with a RTT, but it's likely more dust free than a camper shell on a dirt trail/road). While you've hit on the worst parts of a camper shell (or tent, to be honest) the only other serious drawback to them is that they are not dust free. They're not heavily insulated (I don't sleep a lot outside in the winter and have a nice sleeping bag for other seasons) and lack most luxuries. I think you could utilize a version of Action Packer type modules to store stuff and be almost as versatile as a RTT setup?
I would assume the RTT setup would be relatively dust free? I really don't know? I'm not a fan of going to bed in the dirt, esp. the super fine dust that would be kicked up from dirt road travel.
I'd like something with as much room/accoutrements as my 29' travel trailer, the profile of a camper shell, the versatility of a RTT setup with gear underneath it in the truck and I want it all in a pickup bed package so I can still tow my trail rig behind me. Not sure that's available out there.
Your pickup/camper shell thing seems to be a very versatile rig and I think you'll be hard pressed to make a ton of conceptual improvements. Everything has it's drawbacks.
Something I have looked at that apply's to yours and Paul R's discussion above would be a Bestop Softop shell. I think they'd be reasonably dust free? My Jeep softop is surprisingly dust "manageable" for what it is, but it's not dust free at all. I'm curious if you could start with a Bestop shell and start sealing that up and have something (tailgate area would be the place I'd start to seal up and then keep going where I found issues?)?
(sorry, back to my deliberations about whether to buy a NICE optic (likely the best solution) or an ADEQUATE optic for my 30-06)