Well, I have two of these--buying them even after plopping down dough for 2 WHS licenses and putting together an earlier system from spare parts. What I like about the system is of course the size, the energy efficiency and the hot swappable drives. If you're starting from scratch, this is a hard system to beat with the added 1TB hdd. Putting together anything yourself using comparable parts is going to cost you about the same or sometimes more.
In terms of sound, it's pretty damn quiet, I can hardly hear it as said by others, unless I turn off my main PC and other things in the room. Also there is a nice feature to dim the lights so if you keep this in your bedroom, you don't have to see pulsating blue lights while sleeping or when you turn off the lights. My only caveat would be if you're the type to use your WHS as a PVR or Media Center, then you would want a larger system to add expansion and thus you might want to build your own.
My only complaint with this purchase and I don't know if this affected others was my credit card charged me an $8.66 foreign exchange fee. I know NCIX is Canadian, but I though by buying via NCIXUS that it would be charged through its US division or something.