These type of head units are going to become the standard sooner or later. I was looking at a clarion head unit that accepts USB flash drives/hard drives.
The biggest catch to all these is that navigating whatever device you hook up can be a pain. What kind of track information and such tends to be a bit of a drag too.
Fortunately, my cd-changer in the trunk only had a wire loose and I was able to get it working which will keep me happy until these type of head units improve.
$80 isn't alot, but if you're buying it for USB/SD compatibility its not going to be worth it if you have to spend minutes navigating for the music you want to play. Still, nice find and if someone gets one I'd be interested on what they think of it.
'94 540I 6spd/205000 miles