Adaptive Dynamics - awesome? pointless?

I have it on my SL and with air suspension it makes a real difference. It almost gives me 2 cars, wafty one minute and a tight(ish) sports car (when in sport mode) the next. I use it quite a lot in the SL. I had in on a TT (without air suspension) and it made the ride go from firm to rock hard - on the TT I pretty much always left it in the normal setting – I rarely put it in sport mode.