Which one is more fun to play?
For me atm its zayle but i play both of them rather rarely.
In zayle you have 2 rather mediocre decks but still ok.
Whiz has less viable imo
Both are,
But Whizz decks are much more suitable for the meta right now - you get all the good decks, like big mage, tokken druid, shaman murlock, etc.