NAS is the only way for me.
QNAP 419P with 4 x 1TB drives giving me 3TB.
I get up to 70mb/s over gigabit ethernet quite often, but of course depends what size files you're transfering (larger=faster). Much faster than I've received from USB drives.
Reliable, expandable, fast, engergy efficient, UPS smart, always on and available.
Not cheap for the configuration I got
I bougth the qnap when I was tired of so called gigabit NAS units giving megabit performance (11mb/s for example).