Hey, let's not forget the new 557 that's coming out. This one will have switches on the side so you can mount a magnifier or NVD behind it closer to the EO-Tech. Does anyone have the specs on the 557 yet? Does it use AA or 123 batteries? Does it have integral ARMS mount throw levers or the same mounting system as the 552? If you have a 512/552 the LaRue mounts will put the optic higher up on your rail for a 1/3 co-witness I believe. You can't do that with the 553 though, but it's already 1/3 co-witness with the ARMS mount that's integral to it.