I installed a 280-watt (?) stator to keep up with heated gear and aftermarket incandescent headlight.
Heated jacket liner/gloves/pants (if I need 'em) make a powerful difference on a cold day; a veritable winter sauna!
No heated grips, but . . . having snowmobiled in Labrador in December, I appreciate their worth!
Don't know if the value of heated gear is more psychological than physiological, but . . . definitely, worth the cost if one must ride in the bitter cold, IMHO.
Bonus: I've been gifted electrical gear from an inmate on this forum, and from a riding partner; I'm grateful for this generosity; I intend to pass it on!
Further, I received excellent customer service from Gerbing's, but . . . that might have been under a previous ownership and management--the, "lifetime guarantee" may no longer be effective, or as diligently honored as in the past.