Hi guys

Looking for a replacement head unit. I currently have the std Scoob HU and as we all know it is poo. Trouble is the guy before me has added a 6CD changer which means it's not bad, functionality wise but still would like a better Head unit.
I'm prepared for the fact the CD stacker is going to be useless with a different H.U. but wondering if anyone has any experience or comments on the above unit. It has a USB socket on the front and I was hoping to be able to connect my portable 20GB USB HDD and play the tunes from there but am curious as to whether this unit would be able to power something that size.

Any help is appreciated!
Here's a link to the spec
http://www.raysmith.co.uk/DB568RUSB/