Before somebody else says it, you should really search the forum as most all of these questions have been asked many many times. A vast majority of 45 tac owners use either a Trijicon RMR or a burris fastfire 3 (which is what I use and I love it). Green or red reticle are the most popular. I have not used a vortex razor, but vortex generally makes a quality product. I'm not sure if the vortex would work with the mounting hardware provided with the 45 tac.
I can only comment on my personal experience with two Trijicon RMR02s. They have proven to be rugged as all get out, battery life is excellent, they hold their zero, and the 8MOA dot is a good compromise between speed/ease of acquisition and precision. I feel that it is a high quality product and well worth the price paid.
Here's my $0.02 on the triangle vs dot, I prefer the triangle for long guns and had a 4x32 ACOG on my M4 with orange triangle. The triangle requires placing your target above the top of the triangle which in a pinch requires more brain power -less instinctive- with the dot you place it on your target requiring less brain power -more instinctive- and generally faster target acquisition. Also the human eye does see green better in most instances.
For a different perspective..I acquired my FNX for the caliber, capacity and the reflex optic capability. I was visually impaired, while in the Air Force, which creates acquiring fixed sights a challenge.
I was drawn to the Trijicon dual illuminated since it didn't need batteries and its reputation for durability. Battery powered Trijicons must be removed to change the battery.
I have recently tested the EOTech MRDS and I am sold. The sight is smaller and it uses batteries but they can be changed without removing the sight. The optic has a dot and a ring to acquire a target. It comes with a metal guard that can be used and could be Cerakoted or Duracoated to match your firearm. The EOTech also comes in a light brown or black housing.
Bottom line, for me, the dot and the ring work for my situation and i haven't heard or read any bad durability reviews of it...
FWIW, I change the batteries on my red dots each May when we qualify. The RMR02 on my FNP45T kept it's zero when I changed out the battery last year. I was quite surprised. I popped it off, swapped the battery, ran a couple of mags through it, and it was spot on.
Thanks everyone. Anyone had any experience with the Vortex Razor? When I quickly looked at sights about two months ago in one of our gun stores, I remember the Vortex (red dot only) absolutely POPPED compared to others I remember. The red dot was so bright and easy to acquire. It is pretty much priced like Trijicons.