Biggest problem is players can kill your wisp controlled pet to grief you. Controlled pets will attack each other. Controlled pets will sometimes lock on to a monster they can't attack and won't follow even set on a short leash and defensive. You can get summoned to the boss level and be stuck or your pet will be stuck. You get no credit for the kill and can't even loot the boss corpse when it goes public, you can see the items but it won't let you pick them up. I already saw the post bout invisible barriers that either stop you or lag you. Some of pets don't work as well as others vs the boss.