Here's a quote from a guy who's heard that HST is being used, but just not always admitted to.
"Chris Cormier's trainer had him on an HST routine [with great success] - possibly currently also... Tommi Thorvildsen told me this, and he's also implemented some principles of HST the last time I spoke to him at Gold's in Venice - after being inspired by my articles in norwegian"
For what it's worth, I don't advertise HST. Nor do I pay people to say they use it. I don't pay for endorsements. Of all the pros I've interviewed for articles, none of them used the internet and none of them relied on "training" for size. As long as a guy is still growing using what he needs to compete nationally and/or professionally, there is no need to worry too much about your training (unless you get injured of course). Now this isn't to say that if they really tried to improve their trainign that they wouldn't gain from it, I'm just saying that if it ain't broke, why try to improve it?
For natural guys its a very different story...