I know a lot of people like Kimber, and thats fine, but IMO Kimber doesn't make the same class of gun that STI makes. The guardian is just a better pistol...better slide to frame fit, better trigger. If you like to show off the finish of your gun, then kimber is probably what you are looking for. If you like to shoot, then STI is probably what you want.
Not trying to offend any Kimber owners, they make a solid gun.