We spent quite a bit of time on the range here at Blackhawk and one of the things they've put a lot of R&D and manufacturing effort into is their SERPA holster system.
Ever since thigh rigs became the carrier of choice for deployed troops, the need for an easy to release yet secure holster increased. The old nylon piece of junk that used to hold your M9 wouldn't cut it anymore.
The SERPA takes a little getting used to, but at the end of the day, it's probably the most logical solution for the constantly evolving pistol tactics in the military. Thigh rigs have given way to chest setups and the SERPA mounts just as comfortably on the front of your body armor as it does on a thigh rig, belt holster or shoulder holster. They've even designed a quick release system that allows you to mount the basic holster on any different carrier -- switching back and forth at will.
As you can see from the videos, the SERPA is a pretty good piece of gear even though it took this tactically deficient reporter a bit of muscle memory repetition to get the release point memorized.