I have fairly decent results bouncing down in Logic - albeit the occasional click or silent track. Some people say that you get a better mix by going through a mixer. Gareth Jones (who produced for Depeche Mode) said that he uses a RME as a summing buss, but there are dedicated units like the one by Dangerous. In fact, there were some raging discussions on the LUG about whethere the sound is different if added digitally or via an analog device. I don't know the answer myself. It would seem like a "poor man"'s summing bus to route through a Mackie back in to a separate audio track, and then mix this track in with the rest (after time correcting) - and maybe doing some A/B tests by burning separate tracks to audio and seeing if you can hear a difference. I have also read of people playing their mixes through speakers, and micing them and recording that back to the original project.
