I love the monk, but it's hugely problematic when playing with strangers who are ranged classes (DHs and wizards).
Melee guys have to be in the middle of the action to do damage and build ability points, but they are also exposed to the most harm that way. Consequently, any barbarian or monk is naturally going to want to get into a crowd and do as much damage in as short a period of time as possible. It is not an option to sit on the sidelines and shoot laser beams. And that's what the demon hunters and wizards do. Both tend to play a longer game by chipping away at monsters from a safe distance. Even worse for the melee members of their party, they often retreat from battle entirely until things thin out. In other words, ranged classes tend to hold out when playing with melee classes, leaving the latter to get slaughtered as they face two to four times as many monsters as they normally would.
When playing with strangers, I've done the best with other monks or barbarians, as we have a shared interest in ending battles as fast as possible. It also works quite well when I play with friends who are ranged classes, as they don't just leave me to die.
Ideally, everyone would cooperate and complement each other's abilities. A monk or barbarian should head into the crowds first and weaken them by 60-90% within seconds, expecting that the ranged guys will finish the job once they get there.
Edited by mafoofan - 5/21/12 at 12:25pm