I'm still playing it as a 3-4 of in Painter. And yes, I realize Painter isn't very well positioned, but it's a pile of cards I like to play so I stick to it. It's possibly the weakest card relative to its cost in the deck, but sometimes you just have to keep digging. It also works nicely alongside Jace VP, Dack, and delve.
Fwiw, we just had our monthly sanctioned vintage tonight in Atlanta, and I went 3-0-1 with a 4 Thirst deck. Beat Eldrazi twice, Shops once, and drew with Mentor because I threw the game on my last turn by not keeping a card to pitch to Dack. Thirst was integral, but probably less so than tutor effects finding exactly the right card to combo off.