You're going to get every possible choice of opinions with a question like that, on an internet forum.
That's what makes our country great.
I own many S&Ws, but no S&W 1911. Of my 1911s, one of them is a Sig - it's a "Carry Fastback", which is the all steel, nitron coated, .45ACP, 4", bobbed butt, pistol.
It has rapidly become a carry favorite. It's dead reliable, it's tight and it has gotten even smoother after a few hundred rounds. The factory trigger is better than the one in my new Springfield TRP, which is disturbing to me, as the TRP "should" be better in all respects.
Regarding customer service - right after getting the pistol, the slide was failing to lock back on an empty magazine sometimes. I called Sig. Talked to an actual human within a very short time, they sent me a new slide lock and the CS rep gave me his personal email address as a follow-up. He wanted to make sure it solved the problem. It did. Even though the slide didn't lock back, the pistol never failed to function. Now it's perfect, and their customer service was excellent. My two cents!
Edit: oh... and the price... the Sig was LESS than competing 1911s of that type, and it has front strap checkering, mainspring checkering, bobbed frame and it came with a gorgeous set of rosewood grips. No complaints about this Sig at all, and I've never been a Sig guy. This is in fact the only Sig I own.