Only mentioning it since you didn't, in case you were not aware..... Ibis uses threaded BBs as well. Interesting that the two shops out of Santa Cruz both stuck with threaded when most other companies moved to press fit.
It wasn't a deal breaker for me but I prefer threaded since it's easier to deal with myself, and I have enough creaks and noises on my bikes already I don't really want something that's prone to more of the same.
I'm so tired of hearing the general pressfit complaints, especially because of the irony that there's so many press fits on the bike that aren't considered, particularly one right in the same area as the BB, namely the crank interface with the BB bearings. Fork steerer and stanchions -> fork crown, saddle rails -> saddle shell, and chain links, to name a few more that aren't secured by any other means but friction. Many others that are only lightly secured are cranks, seatposts, pivots (with radial bearings, rather than bushings or ACB), shocks, wheels, chainrings... then there's loose fit stuff, like cables and brake lines.
The issue is that there isn't anything to hold the individual parts together besides friction, and there's a lot of force trying to work it loose, yet people have the expectation that it will hold up. It's chiefly PF30 that is the issue, due to it being tall and narrowly spaced, which is unideal for bracing against the rocking motion of forces going into the crank. PF92 holds up extremely well, and actually provides more chassis stiffness, without taking up valuable space (for pivots, chainstays, tires, cable routing, etc.) like the PF30 does. BB30 axles aren't really any lighter than 24mm ones, and the bearings are heavier and have more drag... not even sure why that took off, except perhaps because it's easier to craft aluminum (splines and threads) than it is to do the same with steel.
Threaded BBs have a history of creaking too, but I suppose it's better than PF30. At least you can lessen the risk of creaking by avoiding metal-to-metal friction/interference fits altogether. For example, Shimano BBs come with a plastic shim that goes between the bearing and crank's axle, which also acts as a labyrinth seal, that adds no additional drag. Will also add that if you're trying to use a 30mm axle in a threaded design, don't expect the BBs to last very long, especially not RF BBs, which still have terrible sealing (I expect the worse when I see people hose down their BB area).
In short, PF30 is
. PF92 is
. Don't throw them into the same fire.
BTW, Shimano and Praxis cranks are the stiffest on the market still. Any force going into flexing/bending carbon and weight weenie cranks are likely not returned in any useful manner. Not an useful place to lose weight anyways, since it's so low and centered. Anyone remember this:
http://www.imtbtrails.com/forum/threads/did-you-know-crank-stiffness.994/