It is a Level 3 Serpa Warren. The lock/release on these are great - positive,fast and smooth but you probably already know that from your leg rig. Have used Blackhawk gear since back when I was on active duty and have never had an issue with any of their kit.
I didn't start off as a big .40 fan but after I got the Dillon set up for it and shot a few buckets of rounds I like it well enough. 45 acp still my favorite though..