Thanks, I appreciate the info. I think I will also call your contact at Koni since they obviously know a great deal about shocks. One of the problems with single adjustables is that you don't actually know if they are set right for your car. For example, since many ITR users seem to put springs with combinations like 600 lbs/in. ratings at the front and 900 lbs/in. at the rear for "serious" track driving (or 400f/600r for more streetable and 800f/1200r for racing), and they are exchanging the springs front to back from the as supplied Tein or Zeal values, a lot of people are not running shocks matched to the springs. Almost all the ITR aftermarket coil-overs are set for higher front than rear spring rates. Also the weight of the wheel/tire/brake/suspension can vary a fair bit which changes the shock's bump requirement, and who knows if the supplied values are correct? Being able to adjust them in both bump and rebound would let you know what the correct value is, and maybe this is why Truechoice supplies both their Phase III and IV kits as independantly adjustable. As for the 1% improvement you mention, that's 1.1 seconds for a 106 second lap at Mosport. That might be quite a lot for some people! I will consider whether the extra $400 or $500 for the Truechoice option is worth it above the Zeal B6's after I talk to Koni.