Random thoughts..
Lots of end user support and easy to find parts/grips/etc for the Kimber...
Lots of out-of-the-box reliability stories about the Kimber, nothing insurmountable, but, tough to ignore.
Replacing springs every 800 rounds for the Kimber can get expensive.... Not sure about the interval for the STI.
Owning a TX-made STI will be nice if TX decides to give the feds the shove regarding firearms manufactured within TX not being subject to federal laws on "interstate commerce"
STI = Local, but there's something satisfying about carrying a gun that's manufactured only a few miles from Mr. Bloombergs city and stamped with a NY address.
Overall, I would plan for some time and $$ to deal with the possibility of having a few startup issues with Kimber.. But that wouldn't scare me away...
I don't own either... but I did shoot the Ultra CDP II and liked it quite a lot...
Just my $0.02