Never shot one, but I've been researching them for a while now and wouldn't hesitate one bit on buying one at that price!
In fact I hope I don't see one at that number, because my gun plans will most likely change immediately!
I like Sigs regardless, but the 556 is just a great gun. Magazines are far superior to that of the AR-15 and everything I've read, praises their reliability, usage and accuracy. It is not
a tack driver, but 1.5-2 MOA is good enough for me out of a piston gun. It's not that
much off from an AR and I am a believer in the system to the point that I'd sacrifice another .5-1 MOA spread to trade for all the benefits.
GO FOR IT!