As my eyes get older I am starting to have problems picking up the rear sight apature, so I'm looking at puting an EOtech. for my AR carbine   (Colt AR15A2 sporter with A1 sight configuration).  My dilema  is should I mount the EOtech on top of the foregrip with a SIR52 or should I convert to flatop route and mount it on the reciever.   Does anyone out there haveany comments/ experience with the SIR52and EOtech mounted on the hand guard of an A1?

Convert to a flat top because it's more versitile.  If you don't like having the EOtech on the foregrip, you're screwed unless you mount it on the carry handle which is too high.  With a flat top, you have another option.  Also, you can use a high power scope on it if you decide to later.  I personally like my EOtech on the upper closer to my eye but that's me.  Another benefit is the flat top will be weigh less.  Don't forget a good BUIS just in case.