Yea, `--statsd-quantiles` seems like a good idea.  As for which values to calculate, I don't see why we shouldn't provide the flexibility.  What if my data is extremely variable in it's processing time and I want to see the 1% timings?  Or what if my message times follow some sort of distribution and I want to see the values for [68%, 95%, 99.7%](http://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rule)?