Overall, I think this is a very well put together, well designed site. Although I'm not a Steve Vai fan, per se, I think any guitar player would be nuts not to listen to what he has to say. This site pretty well wraps everything into one neat package. In fact, I wish other guitarists' sites were like this one.
The best of the site, for me anyway, is the inclusion of articles that Vai has written (mostly from the 1980's). I remember reading these in Guitar Player magazine as a complete beginner and having them go right over my head. Now, some 10+ years later, I get a lot more out of them.
The biggest problem I have with the site is it's download time. It's fancy, but takes way too long to load in my browser (and I'm connected to the company T1... I'd hate to see it at 33.6K). The non-Flash version is sluggish (at best) and the schwanky Flash side of things is downright ridiculous. I'm interested in the info I can get a the site, not the "7, 6, 5, 4, 3...." countdowns that I'm forced to wait through while unneccesarily dynamic menus load.
Other than that, it's a useful, well designed site that I'd recommend any guitar player or Vai fan check out.