i wish sig would just hurry up and make a Ar15 already (and i wish glock and ruger did also) i looked into the ar15, the sig 556, and XCR.
here is my thoughts.
the XCR is slow on updates, slow little company, neat gun. I am somewhat afraid it will be orphaned.
The sig is nice i hear the REAL 550 is the *******, but for some reason they wont sell it to us, the 556 is kinda the bastard step child, like the XCR you dont have a whole cottage industry built around it supplying mods, and accessories. You pretty much better like it out of the box, and like the few mods and acessories sig sells.
DPMS is fair mid level ar15, kinda was asked already, if you are willing to spend over $1,300 and maybe as much as $1,600 or more for a sig 556, why not a LWRC ar15, it has the piston upper like the sig, but most parts are compatible with regular ar15 ... modularity. It shares 90% of the parts with a mil spec ar15.
you can get them for $1,599 but i would personally step up to the $1,795 model with the acessory rail
this quandry is why i dont have a ar15 yet, i started looking and paying attention about a year and half ago ... seeing the writing on the wall.
imediately heard about the awesomeness that is the magpul/bushie masada. i dont know if we will see one in time.
my first choice would be the Fn SCAR but again probably wont be available in time.
a lesser ar15 in hand is worth two in the bush.
get it bush. pun intended.