I took the 2 day California Superbike School fall 2010....
By far the best thing I've ever done on a motorcycle.
Took it in Vegas. Was a bday present from wonderful wife.
I've been riding 30 years. In the first day they corrected a bad body position habit I didn't even know I had on the lean bike, and I had 2 "aha!!" moments that changed my riding considerably.
Not to mention a huge amount of on track time (one of my fellow students couldn't complete the two days - his legs were too sore) and one on one with your very own instructor.
They provide the gear, the bike (s1000rr!), the food. All the instructors are excellent and professionalism is high.
Really can't say enough. The 2 day weekend combines levels 1 and 2, initial outlay's a bit pricey but extremely worth it. If you can do it, do it.