speed is important, as the laptop's ethernet is gigabit, and i hdmi out often. it's going to be the sole network transfer hog. data will be a little of everything. video, music, reference, pdfs, iso's, local install mirrors for *nix projects. camera pictures will be on there, but once i get stuff moved and setup, i'll setup another raid with the retired fileserver, and have a dd take place occassionally, and mirror the directory to another array/machine. and anything really important, write it to a dvd.
in all honesty, its more of a multimedia fun thing.
right now i have zero backed up data, on drives over 9 years of 365/24/7 running. that's how important it is. when moving them case got away from me and landed on the sidewalk. /me shrugs.
i need room, and i need practical speed. my scenario of my parts list fits the bill.