My experience has been totally different than Schmedlap's. I think that I know one guy in group who still uses an Aimpoint. Most teams still have them but they never get used. I would estimate that about half use the Eotech and the rest use the ACOG/J-Point combo. I have never seen many problems with the Eotechs. The J-point needs work but it is currently the only way to have a red dot sight for close range while keeping the ACOG.

SFC W