I'd go Colt all the way. It seems in the past few years, Colt and Kimber have swapped places. I just purchased one of Colt's new 70 series, and let me tell you it's fantastic. Lots of big name 1911 smiths are basically saying that the guns Colt is now making are some of the best that has ever come out of their factory. One of the guys at a local shop (all he shoots are .22's and .45's) put it best when he said "If Colt was making 1911's like this 10 years ago, there'd be no Kimber". On the contrary, I've been hearing more and more negative reports about the Kimbers. Some think it has to do with their new safety "Kiddie Lock" system, I don't know.
I think the Colt would be the better choice right now, for two reasons.
1. Their quality is back to what it should be.
2. It's a Colt.
Normally things like "It's a Colt" wouldn't convince me to make a sale, BUT the fact that it's a Colt is now just icing on the cake.
The other thing to consider is, what do you plan to do with the gun?
Rich