Overall I found the DFI LANParty JR. GF9400M to be an excellent board. It was quick, stable and only had a few minor issues (HDMI 1.3 handoff). This problem is fairly easy to overcome with an add-in GPU. There are many out there that run HDMI and HDCP better than the GF9400 and take up less resources, too.
The chipset on its own is very good and quite capable for such a low-power device. DFI, for their part, have added in their own styling and gotten the board rigged for overclocking. Unfortunately our retail Core 2 Duo was not able to get us very high numbers, but we feel that the DFI board does have the potential there for much higher clocks. Still, even with an inexpensive Core 2 Duo you can get some very good performance out of it.
The LANParty JR GF9400 works best in the role of a SFF gaming rig (with add-in GPU) or as a HTPC (again with add-in GPU), The audio quality form the onboard sound is good enough that even if you do not run HDMI out to a receiver you will get quality surround sound. Its Micro ATX form factor lets you drop it in a small case and the minimal heat from the chipset lets you keep the fans running on low or run it out of the case without the fear of overheating.