I hope I don't sound too harsh in m criticism to Nivmizzet's decks, so I'll start with the one I liked.
I beat my own record of maximum damage with the Elfrakul deck. I reached 6000, then realized I could reach more than that, but that it would imply a lot of tapping and untapping of creatures.
I liked it because even though it had the clunky
Priest of Titania it still was a solid turn 3-4 win. As I remember it, I consistently won with it turn 3.
There were other decks that had a lot of illegal cards such as 4
Mox Sapphire and I don't like playing cards that aren't legal in any format, not even Vintage.
Most of the other decks die to Avacyn's
Glory, and die hard to it. I don't remember beating Avacyn's with decks other than the ones you considered broken. Me being a Spike, I only play against Avacyn's, and hate losing to it.
Did you put your new decks into the CW decks? Maybe those are nice. Do they beat Avacyn's?
EDIT: Also, how will we handle sideboarding?