I have done this mod with a custom made bracket setup that allows adjustability and lowers the seat supposedly 1" from the stock height. I have photo's and a write up of the install but am sorting out some fine-tuning before posting it here. PM me if you want additional info before then.
I can tell you the seats are WAY more comfortable. I have a slew of herniated discs and until doing this mod I was seriously considering selling my car just from the back-pain standpoint. There is no inflating bladder for lumbar support in the GenIII, if you liked that. The seat, low back, shoulder bolsters, and headrest are much improved. The suede keeps you from sliding around in the seat and it "wraps around you" much better all the way around.
The only downside, aside from the increased height (which IS a big deal, even if you're a shorty, at resale time at least) is the visibility out of the rear quarters is a little reduced. I used to be able to look over my left shoulder out the GTS rear glass but now the headrest and shoulder bolsters are there.
Peace.
