Going through some old notes on technology choices, I came across Jason Moiron's excellent commentary on iron.io's performance gains from their switch to Go from a few years ago:
People have commented that these savings could have been gained from writing critical sections in C or by going over the original code with an eye for performance. Putting the obvious parallelization benefits that Go has over most other languages aside, the point they're missing here is that you more or less achieve these results by writing normal Go code.
While I still think Go lacks a lot in terms of language features to make productivity a priority, it's hard to dispute the fact that for a number of cases, Go is better by default. While my notes took Moiron's point to heart, I still chose Python for the bulk of the backend work of Audacious for now, for that exact reason. There are presently a few services written in Go for critical paths, but for the most part, Go is incredibly unproductive, especially in the context of simple Web service related things, which are, by and large, CRUD with one or two bells or whistles.