I attended a 2 day Sport Bike Track Time at Beaver Run a couple of years ago and highly reccomend their program. Their beginner program is very structured alternating track time with class room time. You always ride in a control group so close passes and being buzzed just don't happen in that group. You also have access to the rider coaches for one on one discussions and personal attention. You just have to speak up to get it. I did another single day with them last summer at Mid Ohio and actually had the same instructor. Another very positive experience. They will move faster riders into faster groups and slower riders into slower groups to keep everyone in their assigned group at a comfortable pace for their ability and experience. Both times the beginner group had about 5-6 subgroups based on experience.
I can't comment much on the intermediate or advanced groups as I haven't ridden in those, but based on others who did participate, it appears that those groups are more like a typical track day without instruction but with control riders. SBTT takes track safety and the control riders seriously and will have a talk with you and or ban you if you are being a cowboy.
Best of all SBTT seems to be cheaper that some of these other programs with high dollar names attached.
Check them out here: http://www.sportbiketracktime.com/
Another alternative that I have participated in is Stayin Safe founded by the late Larry Grodsky who wrote the riding safe column for Rider Magazine for many years. His program focuses on the street and is held on the street rather than the track. You won't learn how to put a knee down, but you will learn how to better anticipate dangers, improve your sight lines and to ride smoother. Some of the best instruction I have recieved as I am a street rider and not a racer want to be. Check them out here: http://www.stayinsafe.com/
In closing I will add that my participation in these programs have helped my riding improve by leaps and bounds.