If you are DFing for regular dungeons, queue times are significantly up. There is a small delay (Even for tanks) because as someone said, they are running at full capacity during peaks.

However, for anything beyond 50, specially the new content (Ultima, Moogle, Ex's), you are better off using the Party Finder. Almost no one will waste their time doing it through DF, when setting up a party trough the Finder is so easy.