After further playing I stand by it that this card should be banned from the format.
Its inclusion limits the amount of viable deck types
incredibly. Sure you can do 2 colour or even a competitive 3 colour deck if you have specific answer to only that card. But if you aren't playing aggro, you
need ramp yourself or a t3 counter.
There are literally TONS of decks out there that could be a blast to play, and be competitive without being top tier. Moss just throws it out of the window.
Take this decklist for exampe :
http://forum.nogoblinsallowed.com/viewtopic.php?p=387384#p387384This would probably not be top tier because of inconsistency; but it's a really creative and fun build that has alot of potential. Moss makes it unplayable. You are basically forced to slot in 4 spell shrivel and hope you got it.
It is Meta- defining, way more than RDW/ulamog. Currently
Any deck with green in it is better of for running it, if you do, you get to do powerfull stuff and your opponent doesn't, you get to play enchantment based and landfall based decks and your opponent doesn't.
It makes splashing a colour
Free for whatever it is you are doing; allows you to play death and taxes in simic tempo decks...
Any control deck that is not green based has T3 shrivel or dives.
If you ARE green, there is no deckbuilding recquired to make a serviceable deck. You can just either ramp in a gruul style for T5 fatties or durdle endlessly with lifegain/chumpblockers whilst setting your opponent back a turn T4. The only deck where this fails consistently against is RDW, or Trample/Flier based aggro decks if you don't draw a whipe. Aristocrats is whipe resillient so should be also in that list.
Really a pitty for the diversity of the game.
This stuff is pretty close to FlashHulk/Cawblade levels of annoyance. Throw that card out.