Facebook on both counts. Again, I was shocked. The CPC on Facebook started higher than it ended and the average ended up being lower than on AdWords (By about 10% or so IIRC). So Facebook ended up sending slightly more traffic over the course of the campaign and converted far more users - by large margin, >70% of the total.
So I'm sure my AdWords campaign could use some improvement as I don't think the difference should be so great, but it has been. And again, this is not what I was expecting. I was expecting the opposite.
It feels like this is very relevant especially since you think your next Adwords campaign will be more successful.