I'll throw in my $.02, but it's obviously a bit biased here (I'm an MI for Mad Dogg Athletics, although I am an independent contractor, not a paid employee). I've seen a lot of crazy stuff over the past 11 years of certifying instructors and presenting at conferences. I've also written some of the workshops when I realized there wasn't enough cycling related workshops (the roadie in me). My biggest pet peeve is when instructors don't Keep it Real, even if they don't ride a bike outside (that is, the aerobics on a bike stuff and the super-high crazy cadences that don't make sense).

That being said, you can have an instructor leave an orientation, believe in the program, promise herself (or himself) that she/he will stick to the program and then start teaching at a club where no one uses HR monitors, no one likes to sit in the saddle for endurance rides, the most popular instructors are drill sergeants and do tons of contraindicated moves (i.e. unsafe moves), everything is beat driven at high cadences.... So this poor instructor will start teaching the "other way" in order to be more popular and may even make up a few new moves. Sigh... I guess once they've gotten certified, you can't force everyone to follow the program.

As several have already pointed out, there are some good MIs, and some so-so ones. That's the case in any program. But I think we have some pretty good ones, and if you're in the southwest, the ones I know on this side of the country are pretty good, if not great.

As far as the program itself, it originated from road cycling and is based on sound physiological and training principles. We have always taught heart rate training, which is so very important. There have been some changes over the years, as new things were learned, as well as an effort to make it even more applicable to real outdoor riding. There was a mind-body connection in Spinning long before it became hip to do so (Johnny was deep into martial arts and brought that aspect into Spinning). You can't disconnect the mind from the body, so those who pooh-pooh it (even some of the other certifying agencies) are missing one of the greatest things you can do to improve your performance: utilize the mind-body connection.

My personal opinion, if I can take off my MI hat, is that Spinning was the original, it's the best, and you will not go wrong. But as in everything in life, it's not the end of your education. You must support the certification with CED, with conferences (there is truly no experience quite like WSSC, the World Spinning and Sports Conference, in Miami late May/early June), with reading HR training books, coaching books and articles, etc. Some Spinning CED is excellent, some of the workshops are a little stale as someone said. (PM me if you are thinking of attending one and want my honest opinion on the good ones). The fact remains, MDA and Spinning is an education company, and no one has the type of CED that they provide.

True, it was a bummer when Johnny G left, and I do miss his inspiration, but the program thrives without him and in some ways is even better.

I'm not representing Mad Dogg in this post, I am just telling you what I know from my own perspective! Hope it adds to what you already know...