I like the boxing, because... you can blow things up easily, which others need a group for.
The challenge of tweaking macro's so they do what you want...
The ability to have a group now, at any time of the day or night, and not need to find a tank or healer etc...
The option to ditch an instance for any reason, without offending anyone...
Not having a rogue take the uber hunter bow or the hunter taking the uber rogue fist weapon, because they can...

I detest the collection quests, but they balance out with things like /use item, and having five completes at once.
Some fights are really hard, when you're playing everyone.
Other fights are simplistic with the coordination.