I just reconnected the Sony Optiarc and re-tested the disc in question and it played okay.
Tested on a standalone Philips DVR/DVDr and a Sony BD player and it is fine.
Did a full erase with the Optiarc drive and the Pioneer will now spin the disc up (that's an improvement), but said the disc wasn't empty.
Tried a quick erase with ImgBurn via the Pioneer and got:
W 15:58:02 Potential 'WaitImmediateIO' Deferred Error - (99%, 0/2) - L-EC Uncorrectable Error
E 15:58:02 Failed to Erase Disc! - Reason: L-EC Uncorrectable Error
E 15:58:02 Operation Failed! - Duration: 00:02:20
Are Pioneer drives just bad at reading (possibly) problem discs?
Any suggestions here?
It sucks doing an exchange on the drive over one disc, but I will if you all think there is a reason to be concerned.