After reading the PB subforums (english and german) before even getting my PB 602 I decided not even try to upgrade the firmware
.
Think I have version 2.0.3 on my device.
Even though some errors are more than embarrasing (buggy and laughable battery life indicator) I will only upgrade once I read some positive things on Mobilereads. BTW, thanks to everyone reporting back here it really helps a lot.