Just keep in mind that with all soft holsters you will have some degree of "floppage". Granted I was using a UTG Tornado holster I believe it was, with my 1911 and the amount of flop wasn't too bad. I have recently switched to the Safariland Universal Belt Adapter for my Safariland holster. I used the ITS Tac idea of putting a leg strap between the holster and adapter for extra stability, although with my initial tests without it, it was not as necessary as I thought. Still, it works great and is not as bulky as a drop leg platform.
One thing I do recommend with that route is this. I use a pretty thick riggers belt and just screwing the adapter to the holster didn't leave a ton of room to slide the thing on. So I used the 2 plastic washers that were used on my drop leg platform to push it out a hair and it is perfect. At least for me, best of both worlds.