I respect both of your opinions, Inertia and dodecahedron, but will differ with you on this issue. In particular, Inertia, I am not a Plextor hater, have not said Plextor makes a poor product or doesn't deserve its reputation, and don't feel that I am one of those who you state are using Plextor as the popular whipping boy. Nevertheless, I don't think VariRec is a generally useful feature. Plextor's own marketing literature shows that the use of VariRec at settings other than 0 (the default value decided by the automatic calibration) increases jitter, exactly as Andrea experienced. And a single anecdotal report of unknown origin and unknown circumstances describing successful usage of VariRec will not change my opinion. Even if enabling VariRec truly was the cause for the success that alchip80's son reported, for all we know the actual improvement was due to the fact that VariRec burning is limited to 4x and had nothing to do with the power tweaking that is VariRec's claim to fame.
You have characterized VariRec as a tweak, and I don't object to that. But not all tweaks are useful or helpful, and I have yet to see evidence that VariRec is anything more than a knob to twist for those who get excited about technology, and a knob that in the vast majority of cases will only make matters worse. To me, that is a gimmick. It adds a selling point to help market the drive, but offers no real value in typical usage. And, since you are bringing in dictionaries and calling into question the meaning of the word gimmick, let me elaborate on my statement to make clear my intended meaning: VariRec is, for the vast majority of users and the vast majority of burns, not just worthless, but actually worse than worthless since it degrades burn quality. When I see substantial levels of evidence that show the contrary, then and only then will I happily change my opinion.
I am surprised that you are puzzled by the different levels of skepticism with which Yamaha's and Plextor's jitter reducing technology have met. I find this to be quite understandable, because Yamaha's technology has a sound theoretical basis for reducing jitter, while Plextor's has a sound theoretical basis for increasing jitter. I would naturally be skeptical of any technology, like Plextor's, that is advertised as having the ability to improve some problem but whose first order effects oppose the desired outcome. Did you ever wonder why Plextor never showed eye patterns demonstrating some ability of VariRec to reduce jitter the way Yamaha did for their AMQR technology?