Need best mount for Gen3 G20 Is the new Burris glock mount any good ? the 1st mount do not work well. :-\
The dovetail mount bases are just OK, not spectacular, with any sight system. They place the sight-line too high, too far departed from the bore axis, which greatly hinders variable sight-distance compensation. The dovetail-rail is worse yet, although I use this for temporary testing. A direct drill/tap of the slide is good, a "slide melt" (relief for the sight is milled into the slide) is best. I prefer the drill/tap method, as it doesn't remove any appreciable slide mass (highly beneficial with 10mm), doesn't hinder future mods, and doesn't require further milling to adapt different sight systems. I would consider any sight mount method other than drill/tap or milling to be a temporary solution, and often a costly one. I do my own machine work, which is most cost effective for me, and it is less expensive to drill/tap than buy the mounts, even if you pay a machinist to do it. The "slide melt" machine work is about the cost of the specialized mounts, but takes time to ship it out and back.
I haven't used the Vortex sight, so I can't comment on that. I prefer the FF3 sight over the others I've used, and it's a huge improvement over the FF2. It is very durable and reliable, and holds settings like a rock. I've only had one issue with the FF3, recently. The lens cover over the LED projector came unglued (.460 Rowland slide velocity is quite ridiculous), but the sight continued to function 100%. Burris replaced it with a new retail sight. They were very quick to respond and approve my claim (24 hrs), but the return shipment was slower than Christmas (nearly 2 months).