It was truly amazing, I should have got one of these 10 years ago, the warmth I felt especially around my lower back (pushing against the seat) was carried by my circulation around the rest of my body (yes Chris, even to my exposed feet). It comes with a really handy heat controller which has a fused connector that attaches directly to the battery.
I set the level at about half during the flight and raised the temperature one point when climbing over the sea approaching Table Mountain at about 3500ft AGL. It connects to the controller via a small cable found in the jacket pocket with a male plug similar to the one I power my radio with. The reason for the mention of 'wireless warmth' is that there are other wires in the jacket, the fabric conducts the current, even if you tear it, it will still continue to work. The unit itself draws very little current and I saw no immediate reduction in my battery voltage when I switched it on even without the motor running.

Perhaps I am getting a little older, but this little jacket is now a permanent feature for me. I will never go on an adventure again without it.