I've had both. I now ride with Tourmaster Synergy 2.0 Gloves. I like them much better than heated grips (which I had on my old K-75). With my hands out in the air, heating my palms doesn't help nearly as much as heating their backs, and those Synergy gloves are darn warm to start with. I have a Synergy jacket liner as well and they make a nice system if you ever decide to add more heat.
I rode to work (45 minutes at highway speeds most of the time) at 34 degrees on Monday and was only mildy cool.
As a bonus, I have found that when it is below 37 degrees I actually start to get cold if I ride faster than 80mph. So they are another good reminder to take it easy...