Like others, I'm having problems with this firmware.
I have a Hitachi 79, spoofed as a Lite-On 83v1. The drive has performed wonderfully for years, up to and including LT 1.1.
Updating it to 2.0, however, leads to the red ring/E66 error ONLY WITH XGD3 games. (All my XGD3 backups are BurnerMax, Verbs, not truncated.)
Have flashed the drive with spoofed OSIG, and with stock OSIG, results are the same... Although not spoofing seems to take the drive longer to error out.
I'm nearly certain that there must be a flaw with JF or the firmware...although that doesn't explain why some people seem to be using it just fine...