To be clear for non-Londoners, route 29 has one of the highest crime rates amongst all London bus routes, especially late at night. I'm not sure if it's particularly bad around Camden, although there is probably a higher than average rate of drunken idiots.
Most nightbus experiences start off feeling like fun (yey everyone is in party mood!), become somewhat riddle with a threat of general menace (think A Clockwork Orange) and end up, if you are going far enough, being suicidally depressing because you've sobered up. If you end up falling asleep you will end up in essex, alone and abandoned