Originally Posted by jchammond

You're talking about the quickness & firmness of the shift's? Yes.
The 2 main custom tune software company's are capable/ i'd have to check w/my transmission guy on it being performed without the engine tune software.
The shift light is adjustable; but you probably noticed that when you stab the throttle; it won't shift till right at 7500.
Mine has 85,000 trouble free miles & ive increased the wheel horsepower/Torque to the #'s listed in my signature.
Any of these cars can benefit from a custom dyno-tune, regardless if you've added bolt on's or not,,,as the mfg. sets the AFR on the richer side & you'll have option of turning off speed limiter and having different map settings for Valet, or if some other family member drives & you want it to be governed back.
Both manual & a/t Z's have engine oil temp issues- if you drive it aggressively & spirited; I've yet to add external cooler to mine,as I keep an eye on it.
They offer an external A/T cooler as well.
You will not be disappointed with performance or fuel mileage.
But again- Your Z,,,Get what "You" want! I'm but 1 person & perform my own maintenance,repairs,mods,etc...
Others may chime in on their experiences/ but I find keeping fluid in trans clean w/20-25k interval fluid changes; keeps shift quality good.