I pretty much agree with the consensus here.
DISCLAIMER: Start 2 WR League!
Personally, I have him on my bench, and am dropping him this week, trying to get somebody with more upside.
(Jacoby Ford, Laurent Robinson, Denarius Moore, Eric Decker)
I realize there's downside risk with all those pickups.
I also realize most of those players aren't on most folks' wires.
For me, the logic is this: Crabtree is using a roster spot that isn't likely to start for me, unless:
1) Rash of injuries to starters
2) Bench player excels
So, the roster spot is reserved for upside for me. I don't see a lot of upside for Crabtree. Maybe one game upside, but not bench-player-becomes-starter upside.
In a few weeks, my waiver wire closes for the playoffs. At that juncture, that roster spot may become useful for something else.
I don't envision starting Crabtree in my playoffs, as it's a start-2 league. I have better options, and I hope those guys stay healthy.
All that said, were I in a start-3 league, I think Crabtree makes an excellent anchor WR3 for fantasy.