Apparently many people on I-Club are syaing it doesn't work. I went through it and I think that there may be a "correct" way on how to proceed with the ECU(reset at the proper time).
Got the Unichip, had to reset the ECU during the installation since I unplugged the battery. Ran fine for 3 days then hesitation.
Waited for another week and installed one single 4 gauge cable to the intake manifold and reset the ECU. Didn't want to reset the ECU but messed around, lost the bolt behind the battery, etc...
After the car ran fine for 3 days and the hesitation started again.
A week later, reset the ECU, unplug the grounding mod cable and drove my car for 2 days until the hesitation came back. I got 1 more 4 gauge battery cable. Hooked another point on the intake manifold. And hooked now the 2 cables from the intake manifold to the battery WITHOUT resetting the battery. Everything worked great right away. And now, there is no placebo effect! I had my Wife noticing the hesitation several times, actually she asked me if there was something wrong with the car. She went for a ride again and I asked her if she now notices a difference and she told me she couldn't feel the hesitation. I will not lie, there is a tiny bit sometimes of hesitation when the car is cold. So it will be 4 days now. I will keep you posted in a week or 2. Or whenever the hesitations come back.
I'm not an engineer but a very practical thinking person: I believe after installing the Unichip, the ECU relearned and the car started to be jerky. Adding a grounding mod AND resetting the ECU makes the ECU relearn WITH another piece of hardware and eventually gives the jerkiness again. Adding a grounding mod without resetting the ECU somehow fools the ECU. Now, by writing this I completely understand that the ECU will eventually learn that grounding mod is "there" and start the hesitations again. We'll see. I really hope it can be fooled more or less.