For exp farming I use this build:http://eu.battle.net/d3/en/calculator/demon-hunter#aSgVdh!bhX!cYYbbZ
It is very fun, because you go as WW barb, only you can shoot further. I am just not sure, but to be efficient you should have roundish 150k dps unbuffed to just walk and never come back to finish demons. The catch is that you spawn gloom and rotate inside all the action and with vengeance
passive you collect orbs and never run out of hatred. Another important thing for this build is that you want to have less attack speed, because as bigger attack speed as faster you loose hatred. I doesn't benefit from attack speed.For MP10 and ubers I use this build:http://eu.battle.net/d3/en/calculator/demon-hunter#WQgVdk!fVX!ZaYbbc
The catch of this build is that you keep almost 70% reduced damage and gloom keeps you up with health. Bola shot with thunder ball passive grants you nice stuns for demons not to hit you 100% of a time. This build is also the one where you don't need to stand away from mobs, you always stay in the middle of a fight. If you stop shooting or dropping spike traps - you are dead, since you need damage to gain back life and with passive for crits to restore disciple you can keep gloom almost all the the time.
I run with a bit more then 200k unbuffed dps. I would have more dps with archery and steady aim, but I prefer other runes above dps runes. I think with those classical dps runes I am about 270k dps, but I might be mistaking, because I looked a them long ago :)
edit: if you want to check my profile, when you click on my name in the web address line change "us" to "eu" and click enter again, since I am from EU :)