Paging EDWIN907.....that is the glass whore I take my advice from
He has both setups.....I believe the T-1 and RMR are both mounted on TNVC's SAR's.
I really do find the open, more holographic type sights... like a RMR extremely fast to use and I do hope to pick up a RMR someday, just not for a secondary optic role. With that said....no way do I trust a RMR canted off the side of either a piece of glass or the gun itself...as much as I do the robust lil T-1 that is fully enclosed with no flat sides like the RMRs or similar Dr. type sights. The overall curved body of the T-1 when mounted in a similar type canted position has no where near the strain and potential for a major breakage as a RMR will.
I have no doubts the RMR's are awesomely built, I just think an open, more holographic type secondary sight is really quite vulnerable when being canted and hanging off a rifle.
I do understand Dr. type optics such as RMRs and MRDS's have winged protective mounts....that said...I do not know about you gents, but "winged protective mount" sounds a lil bit feminine to say the least for my tastes