Just like with an adversarial DM, there's good and bad ones.
Bad for the Group:
* I have to add a special case. I've only run across this one guy, but he truly believes that his job as a player is to ruin the DM's plot. Not just adventure hooks, but any possible plan the DM might have. He'll kill any important NPC and destroy any McGuffin. This guy was so bad he annoyed the other players. I booted him from my games, but he was a player in a game I played in.
Bad for the Group:
- Competitive against other players
- Spotlight hog (often lone wolf types)
- PvP types (including treasure theft)
- Rules Lawyers that manipulate everything
- Contrarians* who defy the adventure hook
- Power Gamers that believe they should be able to overcome anything
- Intelligent player in a good Adversarial DM's game
* I have to add a special case. I've only run across this one guy, but he truly believes that his job as a player is to ruin the DM's plot. Not just adventure hooks, but any possible plan the DM might have. He'll kill any important NPC and destroy any McGuffin. This guy was so bad he annoyed the other players. I booted him from my games, but he was a player in a game I played in.