> Aggregating devices adds a huge chunk of latencyIn the situations where I have to do it--and it's less about "buying the gear that suits my needs," more "having to bash together other people's gear on a shoestring"--I find that aggregation ends up around 30ms, which is on the higher end of acceptable when monitoring in-ear. (To be specific--this is not for music but rather audio routing for video. Occasionally I'm on-site somewhere and need to be able to monkey up something a little faster than I'd like, you know?)
Trying to do that with ASIO at all is impossible. So it's a pretty big deal.
> That said, I'm not sure what you think is going on with ASIO, since any class compliant USB audio interface has compatible drivers inherently..
In theory, yes. In practice, I find ASIO a little unstable (my home setup uses Ableton on Windows as a live mixer through a TASCAM US-16x08, though I'll be going back to using a Mac when I get back my Mac mini from a friend). I have never had Core Audio kernel panic a machine, but I've had machines (in one memorable case, the same machine dual-booting a hackintoshed OS X and Windows) hard-lock as soon as I enabled ASIO on two different devices (my old TASCAM US-1200 and my a friend's 8i6).
It is not unusable, by any means, but for my purposes (again, live shows) predictability is a big plus.