O.k, for black friday i picked up two external hds, one was a 1 tb western digital, my passport essentials, that is a portable hd that only uses usb power, no ac outlet need. the other external hd was a 2 tb non portable hd that needs to be plugged in, plus this one uses usb 3.0 even tho i only have a macbook pro 13 inch. In the future macbooks like in 4+ years if i am still usig this external hd do you think it would be a plus to have the usb 3.0 which i am not even using? they both ran me 89.99 which one of them should i keep? i would use it just for my macbook pro, and maybe a netbook a little, im also picking up a samsung galaxy tab that i think has usb. I wont be moving around with it THAT much, if i kept the one that needs an ac outlet at my desk it wouldnt be a hasstle, i plan to use it for my 500 gb hd time machine backup and maybe convert my dvd collection to mp4. Please say which one i should keep and why. Thanks 
