I'm curious if anyone has any real world experience or concrete specs on diamond cut jugs vs. stock. I've been told they help with cooling, but I'm curious about real world differences. I like the look, just not sure about the price tag for adding that feature into a new build.

 

If you like the look, go for it. I doubt the temperature difference is significant.

 

There was a lawsuit a few years ago from a company who diamond cut cylinders, against another company who also diamond cut cylinders. Part of the lawsuit related to "engine cooling." The defendant had done tests which showed no change in cooling from stock cylinders and diamond cut cylinders. If there is a difference it would have to be pretty insignificant.

I had some diamond cut cylinders on a 2003 Softail I used to have and it did look cool. But I don't have a desire to have it done again as it just was not worth the extra work and cost to get it done, in my opinion. You do have to be a bit careful with your hands and arms around them as it is faily easy to get cut.