Interesting, 37signals released their own Golang based version of statsd: https://github.com/noahhl/go-batsd Probably for the same reasons you rewrote it in pure C.
The main reason being that StatsD will max out at about 10K OPS (unless they've improved it recently) whereas Statsite will reach 10 MM. Also, look at the difference between the implementation of sets. StatsD uses a JS object[1] versus statsite using a C implementation of HyperLogLog[2][3]. If you're doing anything significant, you should not be using the node.js version of StatsD.
