I just put the XS Big Dot sight on my Glock. The install was easy and chose to forego the thread locker glue in case I wanted to remove them undamaged. I have 16 steel targets setup down by the creek so I went down to practice my draw drills. With the factory sights I could occasionally get a 1.3 sec draw to first shot. Now it's 9 out of 10 tries. That's from a iwb holster at my 4. As I side stepped through the targets I was amazed at how fast I could acquire the target. I highly recommend these sights! I have 1 target across the creek at 40 yds, it's a 12" plate. It was still very easy to hit every shot. Do not buy these sights if you like to plink beyond 50 yds. The sight gets bigger than the target. Brownells had the best price and shipping.