The nice thing about the ones I have is it makes the grips larger in diameter. which makes my hand cramp less over long hauls.
I vote headed wraps with hippo hands... that's what I have. the hippo hands keep the wind off my hands... and the heated grips puts heat INTO my hands...
though with the ones I have... they on have two settings.... on and off. on with the long hippo hands I traded Fatburg for... they're too hot. for the short ones Trip has they were perfect at anything from 40* to -5* (obviously I was going much slower at -5 than at 40)
I wouldn't recommend the BRAND i have though as the throttle side quit after one winter... but Aerostitch makes a version... and they're a stand up company. I think they're like $45 or so...
http://www.aerostich.com/aerostich-warm-wrap-grips.html
easily removable at the end of winter too..