My wife says the 1999 s80 non turbo seats are more comfortable (softer)as compared to the 2006 s80t awd, with sport seats. How are the sport seats diferent..?

 

Sports seats will naturally be less comfortable, yet more supportive. If you are racing (which is what sporty seats are designed for, sort of...) then you want a seat that will be firmer and more contoured for your body and will hold you into place. Luxury seats, found in the S80 non-turbos (like mine, a 99) are for comfort and not neccesarily stability. I've noticed going around turns at high speeds I move alot to the sides. Sport seats will have higher chest supports and higher inclines on the sides of the seats to keep you from moving around as much.

 

I'd say they're about the same.