Just published the We Got Served review of the HP MediaSmart Server EX475. Hopefully everything you need to know, but if you have any questions, shout!
http://www.wegotserved.co.uk/2007/11/23/hp-mediasmart-server-ex475-hands-on-review/
Tomorrow, I'm cracking open the Norco DS-520 that has been waiting patiently to be opened up, Expect the review to hit sometime next week.
Terry