They're actually very good at exploring and gathering ABS. The small issue they have is, some mobs don't have a metabolism or bones or skin or organs for you to manipulate, so for those you'll either want help or your going to spend a lot of time trying to take them down with melee hits.

At low and mid levels they're mean with mental jolt and a quickened mercenary.

I'm sure the pros will chime in with some tips. I'm not the greatest with muters cuz I usually forget an important buff like enlarge or fly or forgetting i'm still slowed or forgetting to wield my staff and die with a wand in my hand.