I do think that the total carnitine concentration is pertinent and oftentimes not addressed accordingly because of various supplement study directives. It is not to suggest certain carnitine salts would hold pertinence in different settings (in other words, that PLC couldn't be better suited for AR upregulation; just that they don't have the vested-interest studies that are done with LCLT). But, in the sense of evidence-based, a mixture of salts is what I recommend until research does better answer this question.
Now, the problem (for anyone in manufacturing) with PLC is that it frankly is a sticky nightmare in manufacturing of quality PLC source, so - like the COP scenario - finding a quality source may be a true issue. I did mention a supplement on the horizon that manages to do what quadracarn may not - but the snag with its release was PLC, and unfortunately...LCF had to be used to replace production issues and I assure you that projects I am involved in are better-sourced that things you may find on the net elsewhere...period, so the issue is the ingredient unfortunately.
But, yes, I do agree that carnitine salts (Possibly would agree with ALCAR > LCLT > PLC; don't care...probably comes down to total carnitine shuttling efforts anyway...so if you were going to go with one alone, I think even 6 grams of ALCAR would be the primary thought and so on if you could afford it, even moreso with wasted prop blended crap that people invest in or woefully fictitious sh*t that plagues supplement site storefronts) should be considered a staple in every serious lifter and life extension enthusiast period (and yes, Na-R-ALA as a coupling effort with ALCAR would be ideal for those well-versed in the benefits).
See coop, you did generally well speaking for me.