Well I don't agree.
XBMC forces you to do NOTHING. Not in the "file mode". In the "library mode" the organization is quite logical, I had never problems with it.
My HTPC is not much bigger than WDTV - WDTV dimensions are
Height: 1.57 in (40 mm)
Depth: 3.94 in. (100mm)
Width: 4.94 in (125 mm)
Weight: 0.73 lb (0.33 kg)
and Asrock ION 3D dimensions are
195mm(W)x70mm(H)x186m(L)