Nice stories about how iron.io reduced 30 ruby servers to 2 go servers became relevant only after they proven good market fit and working growth engine.
So GO? maybe yes but probably only when the prototyping languages, can't carry weight.
The few seconds of difference is small enough that it effectively does not matter.
For example, I don't have to worry about maps (dicts, hashes, etc); they're in place, but require one additional statement before they use them. I don't have to worry about array lengths; I can just use append(). I don't have to worry about finding a third party library to do network requests, it's part of the standard library (and doesn't require too many convolutions to use).
I do have to think a bit more about pointers when writing function signatures in Go than in Python or Ruby (not that those two languages really free me from that concern: some structures when modified in a function modify the underlying data from the callee as well).