I have a Bushmaster A3 shorty carbine with collapsable stock and I keep going back and forth on whether to mount my EO Tech on the flattop or on a delta mount on top of the carry handle.  Thanks for the input.

Welcome aboard.  The EOTech is MUCH better on a flattop.  Get a good back-up sight, and maybe the larue EOTech mount, if you are concerned with having the irons available.

EOThingies belong on the flat top.

(This coming from a guy who has his ACOG mounted on top of his carry handle!)

I like the flattop mount for the good cheek weld and the co-witness mount.  I have a Bushmaster flip up sight behind the EO Tech, but on the other hand I also like it on top of the carry handle because the front sight is not in the sight picture and I can keep my head up and shoot.  Maybe some day I can figure it out.  By the way, great web site with tons of info.

what is the larue EO Tech mount?

chop that carry handle and use it as a backup site. Keep the EOtech either directly on the flat top upper or get the LaRue mount and have it raised a bit. The LaRue mount does two good things. It raises the EOtech above the front site so that you see more of the EOtech window, AND it allows for repeatable zeroing when taking the EOtech off.

Thanks DOA, you gave me a great idea.  I used a bushmaster rail extension that I already had and raised up the eo tech about 3/4 of an inch which puts it over the front post.  Now I can put half of the eo tech above the hand guard which I couldn't do before because I have a surefire and it is the M4 hanndguard size.  Another plus is I can put my flip up behind the eo tech with plenty of room between the two to operate the switches.  Thanks again for the ideas.  I really don't think I could have done the carry handle mount because it has to fit in the rifle rack inside my patrol car and that carry handle mount would have been too much.