I was at Dataparty 2003 last year. It was a C64-only party, but there were a few PC's too, even one Amiga :-)
Anyway, not that many people, but that didn't stop us from having a GOOD party... Sometimes small parties are better than big ones...
I haven't had any "bad experiences" from Assembly, but Dataparty was... Different... (in a good way) :-)