I have done track days with three organizations so far. Moto Series was my first, so that sort of set the standard. I have done NESBA which was a good fit after doing 3-4 with Moto. Their format was a little less formal, but safety is still number one. I also did one at Mid Ohio with their PTR program. Also different but very fun. Amazing track and facility. I think the hardest thing is to assess your ability relative to the rest of the group you are in. If too slow or too fast, no fun. Either way, all of people in each org were awesome. Knowledgeable and fun to ride with. IMHO.