So what's the basic Demon Hunter M6 spec? I've got 5pc (with RoRG) and a Rucksack, but not much else for notable gear.
Sentry - spitfire, multishot - arsenal, cluster arrow - maelstrom, elemental arrow - frost arrow, companion, either vault or smokescreen (probably vault).
Mandatory passives are culling the weak and ballistics, the other two it depends on your gear and objectives. I think steady aim and custom engineering are pretty well accepted.
Gems are probably: Enforcer, Bane of Trapped, and Bane of the Powerful. Not 100% sure on BotP being the best, but I like it.
Go for cold over fire % on gear, but they are close.
Your sentries have breakpoints at the following attack speeds (taken from your character sheet).
1.........1.102
2.........1.256
3.........1.459
4.........1.742
5.........2.160
6.........2.842
7.........4.154
Stack IAS to reach the breakpoints, if you can't reach the next breakpoint the excess is largely waste
If you have taskers and theo take that into consideration (add an additional 46% for a 46% rolled pair of taskers)
Going from breakpoint 6 to 7 is suppose to be a ~20% increase in damage I hear, I don't know about the rest. Getting 4.154 is pretty hard without sacrificing a lot, pretty sure it is unobtainable without well rolled Taskers, even with a hand crossbow. If you have taskers I'd shoot for 2.84 and an Etrayu (or craft bow until you get a good one). Without taskers, I think 2.16 is what you are shooting for...might be worth using a two hand crossbow if well rolled in that instance.
There is also a lightning build with helltrapper and meticulous bolts, but that is more for fishing high level grifts.