Been using the XR12's for about 5 years now, each winter Oct-March ish, daily on my commute, all weathers (except thick snow). I have them wired straight to bike battery. Always great, always more than plenty toasty, even on long journeys in sub zero temps. The first couple of pairs I had developed electrical faults, either a glove cutting out or bad connections in wiring, not usually lasting more than a winter. But Gerbing's lifetime warranty on all the electrical side has always been held up really well, no fuss, new pair of gloves turnaround in a couple of days - great when freezing your fingers off each day in the winter. Thankfully, they have improved their designs a lot over the years, my current pair are currently seeing me through their third winter and are holding up well. Much better than earlier ones, and seems like they've sorted out the robustness issues.
Overall, I'd definitely recommend them. Even when my new bike came with heated grips, I've still wired in my Gerbings to keep my fingers and back of hands toasty. As for wiring them up, I just cable tie the controller to outside of my jacket, then thread wires inside and down sleeves. Only takes a mo to plug gloves in when donning them, then I just plug controller into wire I have sticking out from under seat hooked up to battery.
Great gloves in general, no signs of much wear and tear, decent knuckle armour and decent abrasive protection on palms too. Always held up fine in torrential rain, they have a handy visor wipe on left glove, and the XR12's have longer cuffs that go over your jacket with draw cord seals, which have always stopped water running down arms fine. Not sure how other gloves they do stack up in comparison, but I'd definitely recommend the XR12's for a serious winter glove.