Both platforms are top-caliber. I've had them both and either one is capable of bringing home the bacon, regardless of what anyone says. What will make the difference?
-Your ability to set the car up (fine-tuning, adjustments, etc)
-Your driving technique (or lack thereof.)
Both cars have their little quirks, some people find the Moog more forgiving in its overall performance envelope, some find the K-Car more planted... All depends on your driving technique. Maintenance is about the same on either car. Any car will break if you hit something hard enough at the wrong angle, so just buy the one that speaks to you and drive it til the wheels fall off!