Well, no, didn't check out the wattage on the actual heaters--good point. I just checked out the price tag! This is radiant heat though so seems like it would work similarly to the hot water kind. Lower heat for a longer time equals higher heat managed by a thermostat.
So the real thing is better, no doubt.
The seat heater is approximately 1/2 the power of the small UltraHeat which is 6.1 amps-advertised for tanks up to 25 gallons. Also that heater is around $100 plus shipping. So my seat heater is not that great a deal if comparing wattage.
I shopped on ebay and the ad said I would get 2 sets but they meant only 2 pads. I had asked first and they said yes, 2 sets. When I got one, I explained that they should change their ad and they sent an extra set--so I got 2 sets for around $40. But that was a fluke.
I was thinking of installing the second set on the pump and fresh water tank inside the RV. I'm mindful of all the power being drawn from the batteries too.
Creativity is fun--why not experiment? :)