I have a Limited with ~1250k and 3 weeks old. I don't use the seat heater often but I've noticed the heating ring clearly protruding through the leather on the butt part of the cushion. The passenger seat has the same thing, that seat's heater hasn't been used for more than 50 miles!
I will have had mine for one month tomorrow - Valentine's Day. I guess I'll have to take her out to dinner so that I don't have issues. The only thing I can complain about so far is that its so much larger than my 3rd gen it takes quite a effort to get it in my single door garage. I don't tell her that though.....she might take offense!