Well, to start,, I generally prefer Rugers.
But as for personal experience,, I've used several SP-101's in our teaching clinics, and carried them. 100% trust in them. They have a very long & proven track record.
The Kimber K6. I've handled a few,, studied them a bit at SHOT & such. Never shot one. In MY hands,, they just didn't feel "right" and weren't as comfortable. I preach getting a gun to fit YOUR hands,, and as such,, I personally didn't fit them very well. Their track record is still to be determined,, as they are too new to having built any reputation.
So,, if I were looking to get one,, my first thing would be the purpose I had in mind for it. If self defense is the purpose,, I'd pick the Ruger over the Kimber. If just a range gun, or any other more causal purpose,, I might consider the Kimber. But that's when pricing would come into play.