After finally installing GordGee's 10-Wire GroundingGear™ system on my 2004.5 5AT Sedan, all I can say is...
OMG!!!!! 
What a difference! Whomever says the GroundingGear™ is just smoke-and-mirrors either 1. is talking out of their a-s, 2. didn't get the 10-wire system (with the ECU and TCU wires), or 3. didn't install it properly.
First, I installed the 8 wires (7-wire + 1-wire system) which took about 2 hours. I immediately noticed that my shifts in ManuMatic mode were smoother and throttle response seemed to be a bit better; the car generally seemed more responsive. However, I didn't notice any faster ignition starts or any change in idle (idled at the same rpm, not any lower) as some others have reported.
Then, later that day, I installed the extra 2 wires -- to the ECU and TCU, which again, took another 2 hours or so due to running the wires through and behind the glove box where the ECU and TCU are located. I took my car for a nice spirited 30 min. drive; much at WOT of course!
That's when I immediately noticed a much more dramatric difference!!!
My ManuMatic shifts actually shifted at the exact moment and rpm I upshifted...
OMG - the dredded ManuMatic upshift delay was gone!!!!
Now, I can bring it up to redline and upshift at 6,500 rpm and it actually shifts right there at 6,500 rpm (or whatever rpm I upshift at). No more do I have to upshift at 6,000 rpm anticipating it will actually upshift at or before 6,500 redline, and no more does my car have a mind of it's own and go into redline, cutting off fuel supply. I upshift in MM mode and the car immediately responds by upshifting into the next gear...WOW, what a difference!
The only negative I have about the GroundingGear™ system is GordGee's instructions; they could and should have step-by-step pictures and he could explain things a little better (for those who aren't auto mechanics or gearheads and don't know what and exactly where the "side strut tower" or "transmission filler tube" are
)
This simple 10-wire GroundingGear™ system has provided much improved performance, especially with the 5AT ManuMatic shifting and throttle response. This is how the G35 should be as stock, but unfortunately it's not and for a fairly low cost, anyone can improve their G35 5AT with GordGee's 10-wire GroundingGear™ system. Although I do not know for sure, but I suspect the '05 G35 5AT's will still have this ManuMatic shifting delay problem, and GordGee's GroundingGear™ is a very good solution!
Thanks, GordGee!!!!