My PWD II shipped with firmware 2.4.3, and it’s been happy as a clam for two years now. Upon reading Paul’s assertion that 2.4.6 sounded slightly better, I bought a 2gb SD card, downloaded the 2.4.6 update, and installed it on my PWD. Seemed very easy.
Now when I tap the initializing screen to see what firmware is installed, it shows 2.9.3.