Damn... That's a lot of money for something that probably equates to a variable resistor. Unless they jack into the wiring harness, which for me is a big no-no.
I'd vote for the PCM. It's the correct way to tune.
A true happy knob goes along with a special pcm tune that will take advantage of specific resistor values for advancing the timing. Really, it's only beneficial for the track in my opinion.
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Kinda sorta, yeah, no?
'02 Black GTP - RIP 03/03/08 ||| '06 Black G35 MT6 - Stock ||| '73 Chevy half ton(resurrected)