None of the C14's have 'over heating' issues. It's something that we don't even think about. However, there has been some discussions, heated, I might add, on the heat management of the 08/09s. I have an 08 and I can't say that the heat is unmanageable on it....in the summer. In the winter, I couldn't beat the heat out of it with a stick. Some riders have had issues with the heat output on the 08/09s, some haven't. I like my 08 and won't trade up until I'm forced too. It has ABS and I like that feature. The brakes are not linked, the newer bikes have linked brakes that to some, affect the riding performance. The 10+ bikes have mods from Kawasaki to alleviate any angst on the heat output to the rider.
With all that being said and I was looking for a C14 now, it would be a 10+ bike although quite frankly and just between you and me, I'm not really crazy about the color selection.