Plus, with a group you can roll over stuff. Non elites are nearly one shots and elites are possible.

This time around I am questing and a little instancing. Last time was almost all instances. Questing (with Joana's guide) does seem to be faster (even though I skip some of the collection quests) than pure instances - but I think that is due in part to already knowing the 1-60 game and 4 soulstones meaning I never have to run back. With mages, aggro was very tricky and I found myself dying to unexpected effects or abilities as well as simple over pulling when I was learning an instance, which usually meant a 10 minute pause to return to my corpses and rebuff. With the locks, it is more likely that a WV dies while the locks keep going - and soulstones every 8 minutes or so certainly speed things up a lot.