Ken, heated seats are like any other luxury item - after having them once you'll likely want them again.
Here in Texas, heated seats are obviously not really needed, but they do show up on cars here. My wife's Nissan Maxima, (purchased used), has them and they are useful in taking the chill off the cold leather seats on cool mornings (it was 33 degrees here today so it does get relatively chilly - I used to live in Chicago so I know what cold is).
Once the Nissan is warmed up, the seats can be switched to the low setting which is nice and comfy - not too hot. On the other end of the spectrum a friend of mine has a new Monte Carlo SS with seat warmers - (he used to live up north and that's why he got the seats). Actually blast furnaces would be a better description for these seats. Unlike the Maxima which takes its time heating up the seats, the Monte could grill steaks on its leather seats after about a minute of turning them on. To my tastes, these things are overkill - useful for the first 5 minutes until the car interior heats up. But my friend loves them for his bad back and leaves his seat on long after I can't stand it anymore, so it's really a personal choice.
Perhaps you could test drive a car with heated seats and try them out for yourself?