I have 3 boys, and the oldest 2 are currently in some type of gymnastics. Most gyms focus on the girls, but not AZOG. My oldest has been going here since October 2005, and really enjoys it. He is currently in Level 2. They have very good guidelines for teaching them. My son is now working on his back handsprings, flips, rings, etc. Even my preschooler's teacher teaches them excellent fundamentals in a very fun way.
The only downside is the current construction. They are in the process of expanding, so it can be kind of messy, crowded, and loud at times. But this, of course, is only temporary.