I was pondering the same question for quite some time before i eventually bought an Aimpoint Micro H-1 (Ill never use nightvision so why pay extra for the T-1?).
The Micro H-1 is available with a 2 MOA dot as well. But I have found no issues with the regular 4 MOA version.
Here is a few things I found out while comparing the two (Aimpoint H-1/ Trijicon RMR) at a local dealer:
The Trijicon RMR is not able to mount lower than the Aimpoint, this is maybe not be a huge deal when you plan to use it as a backup sight, but I bought mine for use on a shotgun, so low mounting was definitely an issue for me.
Since the lens is mounted in the front part of the RMR, you are looking straight into the base of it, which obscures part of the lens. The RMR probably fits better on an AR platform and probably best on a handgun for this reason.
The Trijicon I was looking at was the dual illuminated version, and I did not like the blue-ish tint that the lens have, nor did I like that the dot was very prone to wash-out when I was aiming on things outside (to simulate hunting/targetshooting).
The last reason I went for the Aimpoint was price, but that is a local issue.
Ergo; The Aimpoint is lower, perceived sturdier, and it has very positive adjustment on both "zero" and dot brightness.
Since I bought it, it has been sitting on my Mossberg 590 A1 SP, and so far I have had absolutely no issues.