None of the discs had uncorrectable errors, so that's good. But talking about correctable errors:
Fornet CD-R: The Pioneer had the edge, with the lowest overall C1 count according to the scanning drive.
Ritek F16: Half and half; the Pioneer kept 16x and had the lowest PIF count, but the LG had the lowest jitter though it slowed down.
MBIPG101 R05: LG won, by deciding to go slow at the beginning, though as I mentioned, the Pioneer disc seemed to be poor regardless of the adjustments made by the drive.
JVC-AMS6L 001: Pioneer won. Lowest error count in each category, and had lower jitter.
PHILIPR04: LG won overall in just about every round.
So I guess it is actually more half and half, moderately evenly matched. Regardless, it's hard to say which one outright wins, since each disc model is different from the next, and as you see, discs may burn better in one drive, and the next disc will be completely different.
Just gauge things based on the media you have at your hand. I've always seen people prefer Pioneer drives, just because they handle cruddy media a little bit better, but it seems that LG's BD drives are still pretty darn decent.
--Edit: Oh, and people burn without defect management on all the time. It's perfectly fine to leave it on or turn it off. If you find that your burns fail, try switching the option.
I'm not sure which software burns with defect management on by default for BD media, but DVD-RAM defect management is always on (whereas other types of DVD media don't support it). All BD media should support it, but BD-RE (re-writable) discs probably benefit from it more, since re-writable media is fragile and degrades the more times you overwrite certain areas.