they are both as important. it's only in the US that the campeonato mundial is bigger, due to the major recognition that the gracies have in the USA. since they organize the championship, the american public imediatly thinks this is the major tournament, but the gracies do'nt have the same strenght in brazil, and if you take a look at the media coverage in brazil, you will find out that the copa as big (if not bigger) than the championship. the copa mundial (cup) has more athletes than the championship (they reached a new record this year), plus it has a very large prize money (the main reason why both federations got separated). the only catch is that the gracie-barra RJ boys don't participate in the cup, and the nova uniao guys don't partecipate in the championship... but many fighters give more attention to the cup (because of the prize money).