I'm not a huge fan of the blackhawk holsters. Are you riding a bike? motorcycle? Are you open carrying? Do you need to conceal it? It just depends on what you want the holster to do but there are several better options out there IMO. If you're OC'ing Safarilands line of ALS holsters are a good option as far as an actual secondary retention system. Or you could go with any numerous leather holsters with a thumb break. Any good quality kydex holster should have plenty of retention in itself and are typically the way to go if concealment is your concern as they tend to be low profile. You can also get secondary retention systems on them as well. It really just depends what you're looking for.
I'll post opposing thoughts, as I really like the Blackhawk Serpa holsters. The retention system feels natural to me, with your finger depressing the release and ending up right where it should be when you draw. I use mine for IDPA and when I OC in the colder months and have never had an issue. On top of that, you can usually find them for less than most other comparable holsters.
I like the Serpa for open carry. I try to avoid the Sportsters. I probably have a couple dozen for different pistols and they're all set up with paddles.
I have had nothing but blackhawks thus far but i got a safariland als for an inox beretta 92fs with the suede lining so i didnt chance scratching the finish. Their retention system feels just as right and its next to your body so an outside person cant release the gun
I won't regale you with all of the bad points of the Serpa because so many will get their panties in a wad. I will just relay to you that many training organizations discourage or ban their use in classes. They are popular because they are cheap and have good marketing. Go with the Safariland or Blade tech if you feel the need for a OWB retention holster.
I personally love the Serpa Holsters. I own a 1911 commander and the appropriate Serpa 2 holster. Sits 2 O'clock at a 45 degree front cant and I couldnt be happier. The retention system is very tough and has not failed me despite the repeated use. The biggest complaint is that people shoot themselves in the leg when they draw, but anyone who has any knowledge whatsoever of trigger safety and remembers NOT to hold the retention button through the draw can NOT shoot themselves. The problem is people would hold their finger tightly against the button, and as the draw is complete, their finger will slip into the trigger guard and pull the trigger. Basic weapon safety will prevent this.
I feel that the retention is very natural and synergizes with muscle memory already present.