While I generally agree with the "to each their own" philosophy, I'm more wary in this case.
I'd argue that most folks using the SOB holster haven't had the training or done the practice needed to make it safe -- or even think its necesasry.
You were lucky enough to find the training, and smart enough to take advantage of it. Just where does one get such training?
But, no amount of training will keep you from doing what could be major damage to your back if you fall flat on the holster.
Finally, I would bet its GOT to be slower than a waist-mounted holster -- but I'm not going to be standing anywhere NEAR a guy with a timer in hand, as he draws from that sort of holster, to find out for sure.
(The motions and planes you must go through with that type of holster are more complex and use muscles in a way that is much less "economical" than a standard strong-side or cross draw presentaiton.)
I'm with Glockguy: I'll continue to counsel/argue against their use.