The more I think about it, and read about the problems people here are having, it makes more and more sense that the only way to integrate Logic's Native and TDM sides is not with ESB, but by sending a lightpipe or two from a native audio interface into an ADAT Bridge into TDM. This solves instability issues as well as the fact that for a lot of people, 4 stereo busses isn't near enough. As a film composer needed to print 'stems', and wanting to do so in a single pass, I need to be able to buss groups of tracks and record the results. Since the native audio busses in Logic can not be recorded, but the TDM ones can (you can assign a buss as an input to an audio track), TDM remains of use. But four stems is often not enough, making the ESB a serious bottleneck. But 16 channels is pretty doable, and that's just 2 lightpipes. For that matter, one could do away with TDM altogether, and just use 2 lightpipes from native busses back into itself, and record those onto tracks. problem solved.