Takes 30mins to do a city. Another 30mins to rise cloak, but, for example, can do other dailies while waiting on that.
It might be faster to do Arid if you don't get trained or such while training to pick the ammo, but at least I still prefer city for chance of loots and the easiness to multilog.
I used to do solo dailies before I started getting the Arid tho. Part of the reason I avoid the dailies there is likely from the general annoyingness of the place from doing the quests...