I have no problem with the Serpa, I own one for my Glock 20 and it's great.
The only downside is if you are rolling around in loose material, mud, snow, etc. The mechanism could become caked, requiring additional force that could lead to a mistake. If you're going into a messy environment, I'd say get a different holster.
Regarding the Tex Grubner incident, he's a moron. I'd say it to his face. He switched guns and switched holsters and went full speed ahead, when his fundamentals weren't in place. It was a "tactical timebomb" waiting to blow. It is a bad example for everybody and unfortunately, many follow in his (and similar peoples') footsteps.
I hate to be judgemental, but I am going to be for a minute because it needs to be said. For some reason, firearms, and gun sports, attract a lot of people who frankly should have a less dangerous hobby. People who are not naturally athletic or coordinated think that with a few practice runs in front of the mirror can draw and fire like Chris Costa in the DVDs. It's this "need for speed" that is going to continue to produce injuries and accidents. There are a dozen phrases about going slow, but when the clock is ticking nobody seems to care. They get caught up in the moment and forget to breathe, let alone how to properly operate their holster or maintain trigger finger discipline. That's why I only shoot at private clubs.
Thanks for the analysis Kraig, good stuff.