Full holster is not good - Rounded Weapon Mounted Light Holster

I've used the rounded half holster that doesn't cover the whole slide and those work well. HOWEVER, the full holster that covers the entire slide is JUNK! There is no retention screw. It is essentially a kydex clamshell that snaps over the pistol with a seam along the entire top of the slide. It's pretty useless. The retention is way too tight. I tried it on a Glock 19x with a TLR-1 and a couple of different Glock builds. The fit was terrible across the board. I am leaving my review as 3 stars since the half holsters are actually fairly nice.