I've just added Nezumi Graverobber as I wanted more graveyard removal that was more appropriate to my cube. (In fact, I went back and re-read the graveyard hate thread, and I think you suggested the Graverobber there, Grillo).
I used to be a bit hesitant of it because of the turn 3 4/2 that RBM described, but I'm wondering why I thought that was a problem now. I find the comparison between Ooze and Graverobber odd above though, as I've removed Ooze for being too independently powerful, even though it has +1/+1 counter synergies.
The card rotation thing did give one of my newer players a headache but they got it after I while. I prefer flip to DFCs.
You will probably all laugh, but I've just slotted in
Also Grillo, Stenchskipper always stuck out from your list as odd as well. It might have that interesting mini game but I wonder how fun it actually is? It's just a huge flying beater if you don't get to play the mini game. I might be being harsh, but it feels a bit one dimension and wonder if there was anything more interesting.
I like the idea of Vulterous Aven but that feels pretty low power (says the person who just added junktroller).