Hearthpwn

Diligent Notetaker is such a nice card when you only have single copies of spells. Works really well with :
Devolve to reduce threat/remove good resurrects etc.
Far Sight if you are struggling with draw
Healing Rain if you really need healing 
Hex if you need some single target removal
Maelstrom Portal if you need to clear a lot of tokens
Haunting Visions if you desperately need to discover something to survive the turn
cards created by Zephrys the Great or Hagatha the Witch if all else is used up by the time you draw him

Another star is Instructor Fireheart who can give you so much value if played with 10 mana, or is just a tempo 3 mana 3-3 discover a spell.

If I get Sir Finley Mrrgglton  or Grizzled Wizard in my opening hand vs Demon hunter, then I normally mulligan everything else unless it's early board clear/Reno Jackson/Zephrys the Great. Also very good vs Pain lock which is currently very popular. As well as Aggro hunter which cant keep up without the HP constant pressure.

Always keep Reno Jackson vs aggro of course. Don't be afraid to use Shudderwock as simply another full heal if you need it. 

Because of the many battlecries that add cards to your hand, try only use Shudderwock when you have space to receive a copy of it. If you have an empty board and a fully loaded shudder, then you will need to have maximum 6 cards in hand before you play it to guarantee a copy of shudder in hand. As Instructor Fireheart, Zephrys the Great and Jepetto Joybuzz will add 4 cards in hand (if you have 2 minions left in your deck).

Be wary of Jepetto Joybuzz making your Shudderwock a 1-1 because it can die from Hagatha the Witch's battlecry if you are unlucky.

Finally my win-rate with this version of the deck is currently at 61% with 31-20