The USB drive can play m4v videos from a thumb drive or external hard drive.

i was excited to use this to hook my hard drive up to it

Both those units use onboard processors and ram with up to 250gb hard drives while the Sony BX57 has none of this with only a 1gb onboard memory

I've had a few blu-ray players before and while this one is very good at blu-ray playback, if you want to stream stuff off your media server or expect it to play good video off a hard drive, look elsewhere.