These are underpowered for Divx decoding.
These are barely adequate for full-res video playback due to the integrated video, but should be able to decode MPEG/DVD, "IIRC".
You could probably pry the fansink off and put your own large passive 'sink on it, depending on how you route the power supply intake, use a shroud to direct the air.
IMHO, the best use for either of these is a car MP3 player or a home fileserver or basic/simple webserver, though i have no idea if the hardware has linux support. If you have any question about whether it has enough performance for (whatever), it probably doesn't, you'd be better off getting a similar board that accepts a Tualatin Celry, except for the integrated video speed, which is the only thing benefiting from the C3, with it's 133MHz FSB/Mem support.
It's just a shame that it's @ TD, and this unknown "syntax"... could easily be a TD rebate masked by the word "syntax", i wouldn't put anything past TD after they saw all the ill will towards them from their previous fiascos.