Oh wow... This weekend had Genki-con for animefans in Copenhagen. They had limited it to 200 people participating.
This article now gives some numbers:
http://dkneko.org/2009/06/24/genki-2009-overstaet/ With 23 arranger and 26 helpers, Genki actually had more staff to attend the need of 200 people (staff included) than J-popcon 2006 had to attend to 1000 people.
No wonder I got overworked as J-popcon helper in 2006. And I'm not surprised to hear that most events went as planned at Genki.
Also, I bet all the attending people really enjoyed having room to breathe on the locations. :)