The internet most certainly did not make up the bias drift issue - you can literally find the serial numbers affected by it if you want with google. I've been asked to "fix" like half a dozen of them at least.
edit: It can happen to any of the early ones, but is uncommon in the 90s ones and is most common in 02 and 03 models.... marshall literally revised the board in 2004 to fix this issue that "the internet made up" LOL.
But I agree, they JCM2000 DSLs are great sounding amps, I vastly prefer them to the newer DSLs