Hey Guys,
If your car was built and has a PCM calibration before 8-1-06 (at least for the V6) HAVE IT REPROGRAMMED!!
The difference is amazing. The butt dyno confirms that it has more ass throughout the entire powerband, and the throttle response is instantaneous. Better than my SHO ever was. Now it feels more like an American V6 than a Japanese V6. It has the bottom end grunt that I'd expected after driving an 04 Taurus Duratec, and tranny downshifts are instantaneous. Cruising along in 6th, about 1/4 additional throttle initiates a 6-5 downshift, and full throttle gives an instant downshift to 3rd or 4th with full acceleration. No more duh time.
I can finally say that I'm happy with the car now. I was pleased before, but now I'm happy. No more reservation on extreme freeway maneuvers, because now it just shits and gets.
Oh, BTW, I know the guys at the dealer here locally, so your's may be more reluctant to reprogram, but they still had to put it in as a customer complaint about the transmission not downshifting properly. So, ask them to update the programming, and if that doesn't work, complain about the way it downshifts.