While any school will normally deliver riding improvement, however I find some of the Cal SBK School "Doctrine" to be untrue. Like the one that says, if you have the bike balanced on the throttle (ie;no engine breaking and no power input to the rear wheel) that at full lean a bike cannot lose traction. Get fucked it can't! Ask any half decent racer.
There were a few other things in that course which irked me too.
As far as a learning experience goes, one of the best schools I have seen, is also one of the most unassuming and relaxed days I have been a part of. That is the Preston Motorcycle Club's Bi-annual road race school. It is a combination of classroom and track experiences, as is the SBK school, but, it is delivered by current national A graders who really do know there shit and can fucking ride!
Last Cal SBK School I did, one instructor on his FIM 750cc SBK (an Ex PTR Bike) couldn't keep up with me to give me any tips. The next instructor, who was a mate of mine, had an R1, so he came out to help. He crashed on lap three trying to catch up to me!

I was only doing 1"46's, as I hadn't ridden on a track for 7 years?????
I want someone teaching me, who not only talks the talk, but walks the walk!!!