Originally Posted by amanlikemike
Shouldn't be an issue bob. That said, the QUADLOC lite harness on the R15 and R20 (which were designed with off-roading as the primary purpose, as opposed to the R25, which is more of an all-rounder) has - among other things - more adjustment built into the upper harness and tends to work better with body armor - especially neck braces (which I assume you could be wearing with a pressure suit). If you think you definitely need 25 liters of capacity, it might be worth considering an R20, with a US-5 strapped onto it.
I hope that helps, but do not hesitate to post up any further questions you may have.
Thanks for the feedback. I have been trying a vest for a while and want to go back to the back pack but really like how the vest is carried against the body.
The think I hate most about back packs is the chest strap[ is too high.... or maybe Im just fat.
i was lookling at the 25 because after seeing the 2 chest straps.
now I have to think???????? you give me too many choices