I, like so many others, resisted "plugging in". Once I finally decided to give it a try, it was discovered that it only takes about 15 seconds extra to connect the cables. I have the Gerbing full jacket liner and the gloves.
Any gear that is powered from the motorcycle itself will provide considerably more warmth, and over a larger percentage of area, on most any garment.
We did, however, find out that a BMW G650GS doesn't generate enough watts to power the bike, plus a jacket and gloves.