a stock M45 is slower than a stock GS400? I have driven several stock GS400s and a stock GS430 and 2 M45s - they feel pretty close to me. 310HP Lexus to 340HP Infiniti, bit of a weight difference (favoring the Lexus), some gearing differences, but I personally think both cars are pretty damn decent. Would I pay $50k + for a new GS430? Nah. Would I pay $42k-50K for an new M45? Nah. Is the used GS400 a good value? Yep - considered one myself. But you are damn right I bought a new Q and have loved every minute of it. Haven't had any problem with GS400s walking away from me yet...
Too bad I don't have resources like ClubLexus and the many GS tuning resources to turn to for upgrades and tips. Things in the Q/Cima realm are pretty hard to find...