To be fair the issue varies in many ways based on time of day, datacentre, current popularity of roles etc. Maybe if there were more healer and tank jobs perhaps queuing wouldn't be such a problem for DPS. I wouldn't mind being able to switch between jobs in the same role (e.g. PLD to WAR) but to a different role, I'm not sure it would work as well as we'd like it to.

I think the best way to do it is that SE allows us to send out invitations to players if there is someone in particular that can fill a missing role. So let's say the tank leaves but I know someone who is happy to jump in, I send them an invite and they get brought straight in to it without having to do the whole Join Party in Progress through the DF. Of course parties can still recruit through the normal refill option but I think the invitations thing could help a lot.