Very pleased with the X-FER. Very strong retention at first. I put some gun oil on the light and holstered/unholstered several times and this smoothed everything out significantly. Plenty secure to go standing to prone, run, etc. You can hold the holster upside down and shake the hell out of it and it will not fall out. I've found pushing your drawing thumb on whatever mounting device you're using is a good way to get the light to "unlock" from the holster. Mounts to a QLS fork easily with Safariland hardware. The hardware provided by Armordillo is not long enough for a QLS. Great product I'd buy again and well worth the money.
I like the simplicity, durability and flexibility with the mounting options.
I used this with a sig p220 combat with a surefire x300 and a suppressor and it works great
This has a great fitment with great price and fast shipping!