I've just finished watching the first 45 minutes of ESB, and I only noticed one potential sync issue that I think is just bad ADR (that is, part of the mix and beyond your control). From my notes:

- First sighting of the AT-ATs - "Echo station, 3TA(?) - We have spotted Imperial walkers!" seems to be out of sync.

Other things I've noted:

- There's a weird little "Bong" at the beginning (some CBS/Fox Home Entertainment thing from the laserdisc, most likely), just before the 20th Century Fox fanfare begins.
- Wampa scene: I think this is just an oddity of the 1980 mix, but I don't remember ever hearing the sound of Luke's lightsaber igniting twice in quick succession like that.

Other than that, I have found absolutely no issues in the first 45 minutes. To top that off, this mix feels much clearer than the 1993 mix ever did (I don't remember the 1985 mix of "Empire" very well, so I can't compare this with that). It's wonderful to have the snowspeeder crash sound effect back, too. General room tone and ambience seems to be more pronounced, which is something I noticed with the 1977 stereo mix of ANH, as well.

I have a very strong feeling this is going to be my audio mix of choice for Empire! Thank you so much for taking this task on, DJ!

Now to finish Empire ... (I'm gonna watch Jedi either later tonight or tomorrow, I'll let you know how that goes, too)