I am a semi-professional HS player from Germany who hits legend every season and usually aims for top 200 finish.
Before Un'Goro I really hated the Rogue class and it's playstyle, I never played it and my rogue was level 22 with zero ranked wins. When I watched Dog's stream in the first night of Un'Goro, where he hits rank 1 legend with quest rogue, I fell in love with the deck. I played it since day one and belieave me, I tested all versions which existed until today: moroes, violet teachers, doomsayers, oracle, fans, eviscerates, shiv, bluegills, wisps, crabs, swashburglars, bilefins etc. but I never got a positive winrate until now. One reason was that the deck just was not refined, the other reason was that the deck is just so hard to play correctly so it took me about 500 games until I got the feeling that I have mastered it (meanwhile my rogue is lvl 60 and got more than 300 ranked wins :D). It almost took me 2 months to come to this point and also to find the most refined or best current version of this deck so I decided to post my experiences to help other people who loves to play quest rogue. I started my climb out of dumbster yesterday at rank 4500 with this list and came up to 2000 with just a single loss (against quest warrior). I will post my future results up to high legend of course.
When it comes to the playstyle, mulligan and match up's, I could honestly write a book about this deck but I will start with some tips and tricks for now but will upload a full guide if necessary:
against possible aggro decks (warrior, druid, paladin for example):
cards you can keep:
Fire Fly, Backstab, Glacial Shard (must keep vs warrior), Prep, Tar Creeper, Shadowstep
cards you should only keep with coin:
Tol'vir, Igneous Elemental
against possible slower decks (Priest, Rogue, Mage for example):
Fire Fly, Prep, Shadowstep, Mimic Pod, Igneous Elemental, Novice Engineer
From my opinion, quest rogue has been refined so far that there are 26 core cards with 4 flexible spots for tech choices:
In my case, I chosed 2x Tar Creeper, 1x Tol'Vir and 1x Backstab because it improves my match up vs any kind of aggro deck.
Best possible other cards for flexible spots are:
2 x Bilefin + 2 x Swashburglar (better if you are facing a lot of slower/control decks)
Tips & Tricks:
It is not always correct to play quest in turn 1:
If you start without coin VS druid or warrior, always mulligan for Fire Fly and play it turn 1 instead of quest. You won't fall behind on board which helps a lot in those match up's! If you do have Igneous Elemental as follow up, you can play your quest in turn 4 or 5 before playing the flame elementals + 1 x bounce card!
In general, you best bounce targets are : Fire Fly and Novice (more in slower match up's).
Against Pirate Warrior, the dream bounce target is Glacial Shard since they can't do a shit if you can freeze them while completing quest so always keep Glacial + bounce cards in mulligan!
Vs Druid, you always have to wait until they play living mana before you play vanish! you would be surprised but I can confirm that druid players do the missplay to play living mana into vanish at ALL ranks!
Also consider to keep deckhand in mulligan vs aggro decks, it is necessary to play it early on just for trade their board with weapon + charge and Patches.
Tar Creeper into Tol'Vir can completly shut down the early game aggression of druid, pw or murlocs (your bad match up's until now) so always keep both with coin in mulligan in those match up's ! You can complete quest later on - not a problem!
In slower match up's, you should always keep mimic pod and play it on curve or in turn 2 with coin before you start to bounce anything ! You should also never waste a prep for mimic pod before you have completed your quest! Always keep it for quest or Vanish.
Not sure if this really needs to be mentioned but I heard that there are people who play crystal core into counterspell so: VS mage you should never play crystal core first if a secret is up! Play prep, pot or coin first to check counterspell and even if you do not have any other spell available, you need to wait until you will draw one or the game is auto loss!
There are a lot of more things to consider in different match up's but that is it for now, I can write more if this get's upvotes.
edit: close to top 200 already
Make sure to follow me on twitter for updated decklists.
UPDATE - 06.06.2017:
I started to play ladder 2 days ago and climbed from rank 16 to 5 in just a few hours.
I did the following changes cause I did not queued into aggro decks, only mages and mid palas on ladder:
+ 2 x Swashburglar
Proof and decklist from my twitter:
UPDATE - 19.06.17:
I hit legend with quest rogue yesterday evening with an updated and refined list:
- 2 Boar's
- 2 Tar Creeper
+ 2 Backstab
+ 2 Bilefin
Tar Creeper kind of sucks after the quest is finished and Backstab's doing the same job in early game - you can kill minions like Wyrms, Murlocs and Flametongue Totem (with weapon charge in turn 2). It turned out that you are also not have to rely on the Boar's, in some matches it is great when you can quickly close a game with their charges but after playtesting without them I have to say that you often do not need this charge damage after quest is complete to win a game. Bilefin's are just so strong against aggro when you can bounce the murloc after quest finish! The extra 5/5 taunt won me so many games against token druid, murloc palas and other aggro decks!
Proof and decklist from my twitter: