If your not really into shooting with a K-grip, are there any other reasons to spend the dough on a S.I.R, or is it bst to stay with a M4 GH. ?

                             

SIR free floats the barrel and dissipates heat better than [b]anyting[/b] on the market. It also offers a rock solid mounting platform on the top of your rifle, suitable for mounting any optic under the sun as far back or as far forward as you choose without fearing a loss of zero.

I totally agree with new-arguy on this subject. The SIR-M is mounted on my M4 project rifle and it performs extremely well. In my opinion, this is the most secure and best free float/mounting rail system on the market.

I agree with both of these guys.  I sell and use both Knight's and ARMS products (as well as the Oly FIRSH and other brands) and the SIR is the best free-float rail system out there.

Even if you don't plan to use the foregrip, you never know what you may decide on in the future and this would be the perfect base for tac-lights, etc.

I agree with all four of these guys.

Whoops.  I meant "all three of these guys".  

I just put an SIR-M on my Bushy.  It does an awesome job at cooling the barrel, it leaves a lot of room for adding on extras, and it just looks cool.

Speaking of extras, if you all have time, could you check out my post in the "lights and lasers' section about choosing between the Surefire M900 or M3 Combat Light.  I'd appreciate your feedback.  Sorry KZ45, didn't mean to impose on your post.