You could also look into the Heat Demons grips. I think they are better than stock. You have 5 heat settings. I also Love the heated vests they have.
If you are interested; http://www.heatdemons.com/
Finally installed an OEM set I got from Zip's 45th Parallel Harley Davidson in Michigan
(great dealership to deal with).
What a difference!
Easy instillation & they work perfectly.