I heard that these were very very buggy and had feeding problems when they first came out. I've also heard that a lot (all?) of the problems had been resolved. How does the gun stand as of right now? Most / all of the bugs worked out? And obviously, I'd have to make sure that I buy one that is new from the factory.
Barrels are not chrome lined right?
Barrels are nitrided on the inside, instead of chrome-lined. Last I saw, the insert for the mag shelf had been redsigned to prevent wear from using steel magazines. I don't know if they changed how far the firing pin protrudes on the new ones shipping out now.
Mine was shipped from Sig in February, and has the original (?) mag shelf insert. It has worked flawlessly with brass cased ammo, but I haven't shot any steel cased ammo through it yet.
I still need to take some better pictures...

Slight update, went out to the public range Sat. to sight in some rifles - the Sig ran fine with WWB, Remington Express soft points & some steel Tula (TulAmmo / poly Wolf). The Sig red dot covers the center ring on the targets I had @ 50 yards, but the rifle shoots better than my eyes will allow.
I think I'll leave the dot & single point setup on this rifle - once I get a light mounted it'll be good to go.