Superbike school rocks!!
My wife and I were there 4/2 and 4/3. She rode Level 1 in the yellow group on 4/2. She was the impossibly slow person on the red/black CBR600RR wearing a black Aerostitch.
She had tons of fun and improved tremendously through the course of the day. She has no intention of becoming a knee-dragger...she just wanted to learn how to corner better and more comfortably so that she could enjoy street riding more. She's signed up for Level 1 on 5/1.
I did Level 3 on 4/3 and was having a blast until I lowsided in the bowl.

In a nutshell, I got wheelspin while I was leaned way over coming through the last 1/3 of the turn. I was keeping it leaned to stay in fairly low on the track because there are some ripples about 40% of the way out that always seems to screw me up. Anyway...I came off somewhere around 80-90mph (based on my RPM and gear selection) and slid to the outside of the track. Thankfully, the bike stayed down and didn't tumble. I just slid on my back and ass.
Damage to the bike: all the right-side plastic, broken right handlebar. Damage to me: sprained wrist.
I bought a used set of race plastics, new frame sliders, woodcraft clip-ons, and some other odds and ends. Right now, the bike is ready to go except for the throttle grip, which is on order and should get here Tuesday or Wednesday.
Level 2 is interesting. It focuses mostly on visual skills, and I found it somewhat less immediately rewarding as Level 1. It's a good set of skills, but it just doesn't have the same instant feedback that you get with level 1.
From what I experienced of Level 3, you're back to physical skills, and you get immediate results. I'm scheduled to take Level 3 and 4 at Barber in September.

Oh...some advice about level 2....get on the lean bike as soon as you can. They'll teach you the right way to hang off. I waited way too late in the day to get on the lean bike, and I only got to practice what I learned in one session.