v2 firmware - is for WDMyCloud Gen2
v03 and v04 - for old WDMC (Gen1)
Gen2 have different hardware:
Gen2 vs Gen1:
Marvell armada 370 (2core, 800MHz) vs Mindspeed Comcerto C2000 (2 core, 650MHz)
512 MB Ram vs 256 MB Ram
Custom linux (Busybox) vs Debian wheezy (Mod. debian in v04 fw)
uBoot vs Barebox as bootloader
