Plextor has asked people to stop RMA'ing their drives... and since my drive seems to represent the bulk of PX-712a's being sold, I think it's a good indicator of what to expect from this model. Who wants to have to RMA their drive 1-3 times to get a working unit? That is not the kind of quality people are supposedly getting when they pay the extra premium for a plextor drive.
So pending the release of Plextor's offical "yes we admit out drives suck without this" firmware, I will not be RMA'ing my drive.
And so far, every PX-712a I've seen, whether they burn media ok or not, has not been a good reader. They have VERY low Jitter/Beta tolerances... but hey, they aren't PI/PIF Errors, so they can't be that important right?
Ask anyone who has actually put the PX-712a through any kind of rigerous testing just how well it performs on reading damaged discs, or discs with high jitter. This can be partially seen
here and
here, although neither CDRinfo.com or CDFreaks seem to do any kind of jitter or beta testing or make any mention of this limitation.
However, for my purposes, this is actually quite a good thing

Punch Cards -> Paper Tape -> Tape Drive -> 8" Floppy Diskette -> 5 1/4" Floppy Diskette -> 3 1/2" "Flippy" Diskette -> CD-R -> DVD±R -> BD-R
The Progression of Computer Media