I run all three, depending on what I am wanting to do with the rifle / carbine. I run the EO 552, the aimpoint micro T-1 and the ACOG 4X, all of them mounted on throw lever bases. If I am working beyond 100 yds, I run the ACOG, if I am doing CQB trng, such as clearing rooms, building entries, etc...I run the micro or the 552 - my 552 is NV compatable and I have run it with a PVS 14 for night op's....they are all excellent optics....just depends on what range you are wanting to work at & your intended purpose.....I have also used the ACOG with a side or angle mounted red dot.....so you have the best of both worlds. You can't go wrong with any of these....battle proven...good shooting.