Here are my thoughts on the four DPS classes that I've played, not DPS wise but what they have to watch out for.
  • Bard - it is extremely easy due to lag and late buff display to miss a straighter shot proc. This leads to dps loss. This is the primary thing Bards have to watch. The other thing is their tp. It is very easy (esp when you get lots of straighter procs, or multidotting) to OoTP as a bard. Remember to watch your invigorates. The only other thing to do is mash your bloodletter button between 40% and 60% through every GCD, to ensure you catch all BL procs.
  • Summoner - I hate tab targetting so much, and it is difficult at times to keep track of multidotting. I wish there was some way to track them on multiple targets. Other than that, primary concern of summoner is to make sure pet is in correct position, you're using rouse, spur, contagion on cooldown, and you prioritize which dots to keep up. I also always get miasma and bio II confused, I have no idea why.
  • BLM - sometimes I forget my mana and don't have enough for blizz. Oops. Other than that...preemtively moving and remembering to use the right thunder is all I had trouble with.
  • Monk - Boss turning sucks. Need to watch TP a lot. I don't even use DRG skills because TP sucks. Be good at dancing the flank/backstab line.