At the risk of opening that can of worms again, I attended CSS at Silverstone yesterday.
It was a hot sweaty day in leathers, but I found it to be worthwhile and I'm pretty sure my riding has (and will continue to) improve.
The classroom sessions were easy to follow and taught some essential, basic cornering skills. The track time was essential in applying these skills. It was generally all very sensible riding on track, with only one session red flagged, after two crashes.
So was it worth spending £300 on? I think so. It picked up some real flaws in my riding, which I can now hopefully improve on during future trackdays, and on the road.
I've written a more complete review here -
http://kapitalmoto.co.uk/node/112 I should also mention that my on track instructor was the illustrious (or is that notorious?) Chris Butcher. Seriously though, Chris is a pretty good instructor, asking questions and letting me explore the answers.
TP was also there, but I managed to avoid him most of the day ;-) He seemed particularly busy with one of his students on a new Gixxer K6.