I've done Reg's CLASS, and Freddie Spencer's school in Vegas, and several track-day schools.
Lots of guys will swear by Reg's teaching and techniques, and Laguna Seca's a heck of a place to ride. My experience was, well, barely adequate. He has LOTS of repeat "students", who seem to be there for a track day experience. His instructors are all very accomplished, very fast riders. The intent is to get some individual on-track assistance. I had to track "my" guy down between sessions twice and ask for guidance, and frankly, it didn't help. Classes are quite large, which I see as a detriment.
Freddie's classes are limited to something like 21 students. Guys like Nick Ienatsch and Freddie are the instructors. Jason DiSalvo may be there, practicing; if so, he'll also pitch in with instruction. You definitely get on-track advice and instruction. I'd go back in a heartbeat. In fact, I probably will. Freddie provides everything, including bikes (CBR600RRs). He's apparently going to run schools at the new Miller track in Utah during the summer. Hey: if Freddie's school is good enough for Nicky Hayden, it's definitely good enough for us mortals.
Track Day schools vary immensely. I've done one that approached Freddie's school, and one that was far worse than my Pridmore experience.
Here's a rather longer description of my experience in Vegas, from another forum, right after I attended the school last year.
https://www.twtex.com/forums/showthread.php?t=3478