I've always considered her as a fast, original tron idea (as I said in the 'hipster' tron general thread), something I've been debating trying to make work, if some day I 'liberate' my good equipment from other decks.
But she's still inferior... built-in Hexproof is definitely most optimal and mono-green has no toolbox capabilities. You just need to hope to draw what you need at a given time.
Vigilance is pretty hard to come by in mono-green, and super useful in multiplayer games. I think that's the one thing Mirri has on Omnath and Thrun - She's almost always unblockable so you really never have a reason not to attack with her every turn.
Card advantage is not the same thing as card draw. Something for 2B cannot be strictly worse than something for BBB or 3BB. If you're taking out Swords to Plowshares for Plummet, you're a fool. Stop doing these things!