Short answer regarding frameless: I simply don't like frameless.
As for volume, my (much longer) answer is a little fuzzier--and you may be right.
All tents are HS Tarptents (sorry, no tarps, gotta block the bugs). All the sleeping pads are full-length el cheapos that strap on the outside of the pack (sorry, can't sleep with my feet on the ground--or ask others to do so). Mess kit is compact enough (though not as titanium as I would like it to be). First aid and general ditty bag stuff is much more expanded than what I normally carry, since I am taking somewhat inexperienced teenagers who might be accident prone (testing, testing: does Axe body spray/deodorant/shampoo/etc. attract bears? We are DOOMED!). I can't afford good sleeping bags for this trip, so we're doing $30, 3 lb sleeping bags, which don't compress worth a crappola (aarrggghhh). In general, teenagers pack too many clothes, too much food, and tend to haul stupid crap (yes, one is bringing a hatchet).
Still, none of this explains the volume I'm collecting here. Hmmm...