Konrad, that's awesome! I think DTS would be a better name than "T-Rex". The "T" is actually really simple. The top of the main stay just slides into a pocket at the top (see first picture) and then a separate piece of metal (sewed into the gray fabric) is directly connected to that pocket. The head of the "T" is not completely fixed - it can angle to each side a little bit. So I guess all the weight of the pack really hangs from the top bar of the T, which then has a pocket to transfer the weight to the main stay, and then down to the hipbelt.
Ken, how big is your bear canister? I have never used one. I do have an Ursack stuffed completely full inside the pack. It cannot fit horizontally but it fits vertically with room to spare in every dimension. I currently have a Granite Gear Blaze AC 60, REI Flash 65, HMG 4400 SW, and ULA Circuit. The pack's dimensions are very similar to the first 3, except the HMG pack has a larger extension collar. It has much more interior volume than the Circuit.
I have an 18.5'' - 19'' torso and there is approximately 3'' left of adjustment for me (maybe 3.5''). My guess is it will work for up to 22'' torsos, +/- half an inch.
Regarding the lumbar pad, I discovered the pressure I was feeling is actually from the webbing buckle near the top of the lumbar pad (see 2nd picture). By velcroing the lumbar pad a little lower, I am able to reduce the pressure I feel. After doing this, I carried the pack around for about 30 minutes with no problems. The suspension system is really effective. Again, 100% of the weight on my hips with 35 lbs. 25 lbs in the pack is barely noticeable, but trail miles will be the real test. I'm taking a wilderness first aid course this weekend, but hopefully next weekend I can get out for a hike.
The Blaze AC 60 and Flash 65 are going back to REI this weekend. This pack and my HMG 4400 SW seem to easily carry better than both of those.