I went back in 2001 and it was a great experience.
We had a master class beginning every day at 9am and I remember the first morning being there sleept but nervous as hell, and then Gary came in with his little fluffy white dog and he was so nice to everyone (I was still terrified!) We had to play something in masterclass every other day, which was a little daunting, especially for me who had only been playing for about a year and a half at that point- I didn't know a lot of music to begin with.
"Vomit" was a great exercise for shifting, but it was tough shifting all over the Gstring that early in the morning!!
One thing that I didn't agree with however was his constant pushing to play with your bow as close to the bridge and as slow as possible in an orchestral setting. His sound is very characteristic of him but I don't think playing that way in a section is going to make you any friends
Also, you do go to his house a couple times- for dinner, and he even plays a recital for you with harmon in their personal studio. When I went the Amati was still at his house, so we all had a chance to play on it a little.
All of the people were great as well, very open minded and at all different levels of playing. Tell us how it goes!