I can vouch for the N40L. I bought one for a sweet price, and then decided I need to stop buying so many thing just because the price is good. Therefore, I wound up selling it to a friend while it was still en route to me.

I helped him put Ubuntu on it and he's using it to feed a Popcorn Hour (Samba shares) and I think he's also using a Roku with it now (running Plex Media Server on the N40L, I presume). I will have to ask him about it...

I've also been looking at getting a new box to hook my Drobo up to. I've been eyeing this Foxconn barebone which seems perfect aside from the USB 3.0 ports being on the front. It's even coming with a 60GB SSD through a promotion currently. If you want it out of the way, it comes with a VESA mount so you can stick the thing to the back of a monitor with the proper holes.