I always had a WD HDD as a second drive in my old but reliable MBP. What always is (was) a pain in the a$$ was that this drive always went to sleep, regardless what the energy saving settings i made. So sometimes when i dropped a song to a deck and the hdd just went to sleep, DJAY showed the beachball of death. it even crashed sometimes! So i decided to buy a big SSD but i am still unsure what is the best filesystem.