This is my first post on this site, I finally feel I have something to say worth something.
I have also been trying out quite a few holsters for the browning. Here are a few things I have found, and I'll try to stick to comfort, security, and operation under high stress. (By high stress I mean loss of fine motor skills)
I had the issued Bianchi holster (http://www.bianchi-intl.com/product/Prod.php?TxtModelID=UM84III) for Roto 8 Op Palladium and although secure, it had several problems. The dropleg thigh adapter is very stiff and is a poor choice when getting in and out of vehicles and can be uncomfortable. The big flap makes drawing quickly very difficult and in a high stress situation the little hook on the bottom is hard to manipulate. Overall it is my last choice.
I then purchased the Blackhawk Omega VI dropleg with thumb break for the browning/1911 (http://www.blackhawk.com/product1.asp?P=40MLH1&C=C0902) . Fits the browning great, and the dropleg is more comfortable than the Bianchi, but a good belt is required to attach it to. The elastic thigh straps are great compared to the in-elastic single Bianchi straps. Quick draw with the thumb break, HOWEVER, the thumb break strap doesn't work well when the pistol is cocked. So, drawing is quick, but then you have to ready it, costing time. Reholstering blind is sometimes difficult but muscle memory practice can fix that.
Next try was the issued black safariland. http://www.safariland.com/product.aspx?pid=6004 . The thumbreak style is much better with the rotating head than the Omega's strap, and the molded plastic is fantastic for drawing speed. I really like the comfort of the molded plastic platform that rests against your leg as well. However, the problem I have with the rotating thumb break is that you are drawing the pistol with your 4 fingers and don't get your thumb around the grip until the band is rotated forward. This costs very little time, but hey, we are being picky on purpose here right? On that note, the fit of the browning in the holster isn't perfect too.
The Serpa level 2 tactical thigh (http://www.blackhawk.com/product1.asp?P=43050&C=C2094) is what I am using now and for me, is by far the best! I purchased the dropleg version that is made for the 1911. One problem. The pistol fit perfectly, but the slide locking lever pin on the right side sticks out causing the operation of the release to get caught on the pin! So, easy fix with the gerber. A small groove cut in the release makes this holster as smooth as butter. (I'll add a pic of the groove i cut) I like it better than the safariland because your hand is in a perfect grip from the start, the pistol can be readied and on safe in the holster, and your trigger finger is automatically lined up with the trigger guard. It has a large open top so re-holstering blind is easy. Comfort wise it is the best! Big molded plastic back and elastic leg straps are super comfortable and it has two drop down straps from your belt so they don't get in the way of your pocket. Plus, the LCF is very high with this holster.
I liked it so much that I bought the smaller duty belt version and attached it with malice strips to my tac vest in a cross draw position. I like the cross draw for quick transition drills and when working in tight spaces. It is very quick to draw and punch out but I have had it catch on my sling a few times.
I'll be adding pictures of my rig as soon as I take them so you have a better idea.
Overall, I recommend the Serpa to the troops in my coy, the only downside is cost.