I just received my Eotech 553 FDE and to my HORROR, it has a set of QD's for rail mounting BUILT into it! As in, they CANNOT be removed unless you disassemble the WHOLE UNIT. It seems pretty solid though, and are made by a company named ARMS, but you cannot tighten or loosen tension easily like you can with Larue, and does not have a locking mechanism.
I wanted to mount a Larue LT110 with the adapter for my PVS 14. But now I can't.

Even though I was planning a FDE build, I am probably going to return these  and get the eotech 552/LT110 Larue Combo

What are the differences between the 553 and 552? Besides available colors?

Thanks

The 553 uses two CR123 batteries. The 552 uses two AA batteries. The 553 also has a small amount of extra height built into it. The 553 has been plagued with reliability issues that may or may not have been solved.



I would recommend the new XPS 3-0, it is NV compatible and uses a transverse mounted single CR123 that should alleviate some of the issues that cropped up with the other types. I have been using an XPS 2-0 with success for a few months, and have yet to see any reports of issues like the 553s had.

Hmm....this is the first I've heard of it.  I've been running a 553 on my entry rifle for well over a year and I've encountered ZERO issues!  Great optic...a tad bit heavy but it's solid!