All the info you could possibly want and more:
http://forum.saiga-12.com/
I have one, and while it's been reliable, in it's stock form there are a few drawbacks. My biggest complaint is that it lacks a bolt hold-open feature, which means either holding the bolt back while loading a magazine, or else having to press upward very hard to compress the springs in the magazine (the top shell hits the bottom of the bolt if it's in the forward position).
I'd like to send mine off to Tromix (
http://www.tromix.com/Welcome.htm) for some improvements, but they're so backed up that they're not taking any more orders until 2009! Guess I should probably get on the waiting list...
But it's definitely a unique gun and it's gotten a lot of questions and stares from people when I've taken it out before!