I do :) HST was one of the most successful programs I've done, as far as increasing muscle mass is concerned. I'm sure I still have my before/after measurements around somewhere, but I did put a permanent ...... oh, I think it was a half inch on my biceps that hasn't gone away. Everything else I measured increased as well, except the waist. That was over just an 8 week cycle.
I did a few runs of HST, just the plain vanilla one off the website, a 6 day a week version, and one I got out of Vicious' (an HST forum member from back in the day) ebook. I think I have the ebook if you can't find it online. Anyways, I did his too. So several difference cycles. My routines now still look like my HST runs did: compound moves like benching and squatting, eschewing annoying stuff like cable curls or flyes.
If you really boil it down, HST is a simple linear periodization program, which haven't really failed anyone ever. Once you finish the cycle, you just add 5-20 lbs to each lift and start over. That's a feature of a ton of successful programs (5-3-1, Korte 3x3, Coan's DL, Smolov [I think]etc etc).
BLAH BLAH TLDR Yes, it's fucking awesome.