Only reason I'd shy away from a SIG GSR is that it has an external extractor. I'm not saying it has extraction issues, but a 1911 IMO should have an internal extractor. To me it's just more aesthetically pleasing.
Lately Kimber has been getting a bad rap on their quality control. I've heard that the Kimber II line has had some problems and some folks have had to send their pistols back multiple times. I'm sure with the amount of pistols they churn out, there are going to be some "bad" ones but if you're paying a hefty price for the Kimber line, then it should be right the first time IMO.
Edit: Oh forgot to mention that I bought a used Kimber Custom Series I. It came with some no name magazines and they kind of give it problems feeding. It also came with a 10 rd chip mccormick mag and that has been rock solid. I'm on the lookout for maybe some Wilson ETMs or 47Ds, or even some Tripp Cobra IIs to make it feed reliabley. It's a great shooter and still breaking in 'cause the last owner said he only put like 1k through it.