I do my mixing all ITB (no outboard anything) on a Mix+++ system, so I do the AES out and back into another AES input and record onto a new stereo track in the same session. I do that because I've heard that the automation does better on playback than on Bounce To Disk. If it's not a complicated mix, BTD is fine with me. Then those 24bit files go on the hard drive or CDR or DVD for the mastering guy, unless it's me, and then I just load them into a new session and "master" away (In "quotes" because I certainly don't consider myself a mastering guy, especially ITB). And again, because I'm all ITB, I do everything at 44.1 so it's painless to go to audio CDR.
Probably not "the ideal" but it works as well as if found with my resources.