There are things that I like about FW 2.02 better and things that I like about the newer FW better. 2.02 is more "natural/easygoing" up top but lacks some impact and seemingly, extension down low. The newer firmware is more dynamic/lively but with HD800 & depending upon tubes I can find it edgy up top.
PSA has said that the big difference in the original 2.02/3 and the modern firmware is a streamline of the code and process time. Ie. 2.02 had higher jitter which in turn means less focus,less immediate. Jitter is one of the those interesting things in that high jitter is bad but small changes to relatively low jitter can fine tune focus and immediacy. I like razor sharp edges to my music re-production, some may prefer fuzzier lines that are still distinct.