Thanks everybody for the thorough and prompt responses.
McHale is out of my league. Aarn doesn't look like what I'm looking for either. Here are a couple questions about the other packs folks have mentioned, but really, if anybody in the bay area has a tall Exodus, Porter, or Circuit I could see in person, that'd be great--PM me.
The new Jams look to have much more going for them than my old one, both in terms of a stiffer hipbelt and with it apparently being placed inside from the edges of the pack. On the original Jam the hipbelt wings are sewn into the seams at the very edges of the backpanel. This is fine when the bottom of the pack contains a mostly-lofted sleeping bag and the whole pack can wrap around me, but works less well with a fuller, more rigid pack. I'm a little worried, though, about whether that change would be enough to bump it up to carrying 25-30 lbs comfortably.
Relatedly, for the MLD packs, I'm worried that the hipbelt, although more than webbing, has the same issue as my old Jam. Although maybe with the extra rigidity being attached at the outside edges isn't such a big deal. I have an MLD bivy and love the quality of Ron's work.
On the HMG pack, since Cuben is new to me, I'm worried about it's longevity. Also, how is the construction quality on these packs? I haven't seen any HMG gear, but some of the BPL review pictures have what looks to be pretty irregular stitching. http://cache.backpackinglight.com/backpackinglight/images/hyperlite-mountain-gear-porter-pack-review-4.jpg
I don't know anything about the ULA packs. As I said, if anybody has one nearby me, I'd love to see it.
Thanks again everyone.