[BrianG]

Fins will aid cooling, no way to dispute that. How much it will help will be hard to say unless someone has the finned/smooth versions of the same motor, ran both, and took temps after the same length/type of run. Seeing as how Neus are quite efficient, I think they'll stay fairly cool no matter which version you get - assuming of course you are gearing properly and have a properly sized motor to begin with.