If it's slide-mounted and farther forward, it's harder to track, however, because the muzzle will be jumping around as you fire.

Here's my Open division Glock 34.



I started with a Glock MOS, so it's a little different than what you'll need to do. With the MOS series, there are (poorly-designed) mounting plates that all have different post and screw arrangements to accommodate basically any micro red dot on the market today. With a little work, I was able to mount up this Burris FF3, and I'm really happy with it. For you, you'll have to send the slide off to get milled. Even though it seems like everyone and their dog is offering RMR milling as a service now, I'd only go to reputable shops for this. I've seen too many slides get really buggered up by shadetree gunsmiths. Reputable services that come to mind:

Glockmeister
ADCO
Suarez
Class 3 Machining (although I know them for their barrel threading services, I'm sure they'd help you out)

Once that's done, you'll be able to mount your optic (more than likely a Trijicon RMR) and have some fun with it. However, you're probably going to want some taller sights to cowitness with the dot. If you're trying to get shots off quick, it's actually easier to pick up the irons for the first shot. If you don't have cowitnessed sights, you'll be doing the dot wiggle trying to find it in the window. It's not necessary, but I highly recommend it for most shooters. I don't have them on my Glock, but that's because it's just my preference to only have the dot.

Are all cuts done for the Trijicon?