This Tues 9/5/06 I will be dumping individual GB tracks to my friend's Pro Tools set up. I hope all goes well. I'll report back to tell folks how things went because I know this is a topic that comes up fairly regularly. Make sure that you include a count-in click track (1,2,3,4) with EVERY track you export. this will make syncing up the tracks easy. All the tracks will appear in iTunes with the same title (the title of the whole song) You then should rename the tracks according to what they were in GB like Trk 1 guitar, Trk 2 Drums, etc. Make a track sheet on paper as a guide. Make a mix of the song and always keep it with the individual tracks so you'll have a mixing guide when you reassemble the tracks in pro-tools. Don't add too many effects and don't make them too extreme. You can always add reverb later but if you add too much reverb or whatever on the original tracks, you'll be stuck with that sound and won't be able to reduce it. Try not to let instruments "share" tracks because it will be hard to mix them later. It will require alot of automation which is very time consuming and uses extensive CPU which can cause crashes. Also: export all tracks in the center panning position. This will give you the fullest sound possible per track and you can always pan them more effectively in Pro Tools.
Panning in GB is less than stellar. (imo) And GOOD LUCK!