Disclaimer: After nerfs I speculate that demon hunter will drop to bottom tier and the outlander hero power will become unplayable. I would no longer recommend playing the deck with the new hero power change, Hunter, Warlock, Priest, and Mage are your safest bets in the new meta.

Playing at 8.9k mmr in casual, I've fallen in love with the demon hunter playstyle in duels getting around 260 wins (and finally getting a gold Demon hunter Portrait). I've felt that this version of demon hunter is the best you can find, as I personally much prefer it to the Felosophy, Desk Imp version of the deck. Demon hunter is able to easily reach 8 wins at least with useless passives, and 12 wins with even one good passive.

Bucket choices: 

      When choosing buckets to add to your deck, try your absolute best to only take cards that are 3 mana or below, only exceptions are aggressive buckets with Il'gynoth, Kayn Sunfury, or sometimes Frenzied Felwing. Soul fragment cards are a trap, and you should aim to only take aggressive cards.

Passive Choices:

      1st Passive:   Spell related passives are best, rhonin's orb, fireshaper, plaguebringer, robes of shrinking (in that order) are the best options you can take. Crystal gem, sandy surprise, ever changing elixir, passives are passable as well. Just take whatever best enables you to have a good start and be aggressive.

      2nd passive: Same as first passive, spell related passives are best, double time, khadgar's orb, and emerald goggles will allow you to almost always reach 12 wins. The reason demon hunter is so good is that, unlike hunter, even if you whiff on passives you can still easily reach at least 8 wins, (one of my proudest achievements being reaching 12 wins with caltrops passive). 

     Treasure choices: Treasure choices can be tricky because of how many there are and how they rely on your passives and deck, but I figured I would list the best ones that come to my mind.   Locusts, bag of coins, grimmer patron, bag of stuffing, phaoris' blade, pure cold, enrage (previous two are almost autopicks with double time), worshipper, party portal.

      Card choices: As mentioned earlier I felt that this version felt better than the Desk Imp version of the deck. Felscream Blast is a tech choice as it deals easily with Boneweb Egg from warlock and can easily be cycled for outlander/ Pen Flinger damage. The only card I would say you could switch out for something else if you want would be Shadowhoof Slayer for any other low curve card.

Thanks for reading my guide and good luck! Feel free to ask any questions!