Pari lainausta noiden valmistajalta ja käyttäjiltä, puhetta lähinnä heidän tarpeistaan ja tuosta pistoolin paikasta:
Also if you look back at a lot of the rigs we have done for seals in the past few years they are set up to carry both m14 and m4 mags. The rigs all carry a pistol but im not sure they are so worried about the pistol.
we generally try to keep anything off of our legs, this being for obvious reasons. i didnt like running around getting shot at with a drop leg holster and all kinds of other shit hanging off of my legs, its just not smart thinking. i also tried the pistol in the rig thing and i didnt like that either. so now, i am completely sold on dropped and offset holsters. i bought a blade-tech doh with a 2.5" drop and had a back plate done by rich shaefer of custom carry concepts that was for a 3.5" drop, it clears my kit and draws smooth. i also had rich make me a dropped and offset double mag pouch, it is also a 3.5" drop.
there are guys out there that still role with drop leg holster, mag pouches, and every other thing they could find to put on their legs, its just a matter of preference, maybe they havent had to run for their lives yet.
When your M4 is in your shoulder your firing hand is about five inches from where the pistol is carried on the chest harness. This makes drawing it while transitioning MUCH faster.
The other scenario is when you drop your M4 to transition to your pistol you move your hand all the way down to your drop leg holster then all the way back up to present the weapon. MUCH slower.
Try it and you'll see. This is how I run my pistol on my Eagle RRV.
One more thing... Pistols on your vest means one less thing on your leg to slow you down. I friggin HATE drop leg rigs.
Pacathan kulkevat pantacilla nimellä SVS personal body armor, 
