The answer is always 'something other than Kimber'.
I've fixed entirely too many of them by owners who were at the end of their rope, still having a gun that doesn't work even after sending it in five or six times.
The shit of it is, most of the problems were simple.. poorly cut extractors, too tight of a slide to frame fit, rough feed ramps, shitty mags. I get annoyed when I have to clean up after a home tinkerer, I get pissed when I have to clean up after a manufacturer of a $1000 pistol.
If the stars align, and the union pukes are having a good day, Kimber can make a pretty good pistol.. but there are better 1911s out there for the same or less money.
The VTAC isn't that great either though.. the sights suck. If you REALLY want an FDE M&P, go for it, but I'd just get a standard model and a set of Trijicon HD sights, and spend less money in the process.