I know its the wrong time of year (or should be) but if you have them, or had them, on a bike do you think heated grips are any good?

I had a free set of Oxford heated grips having subscribed to Ride magazine and am in two minds about fitting them.

I do suffer with really cold hands but only ride the bike for fun tending only to go out when it's reasonable warm.

I'm also a bit worried they may make the grips a bit to chunky. I only have small hands!