We noticed odd issues with our production metrics and realized that Instrumental was either averaging or overwriting metrics that were flushed more often than the highest supported resolution (60s). To solve this we increased the flush interval to allow the metrics to be aggregated by statsite. This greatly improved the accuracy of our metrics and should be noted for anyone using our sink.
The documentation on the difference between the two is minimal but it seems that an absolute gauge will always overwrite the value with the last one received. Based on this it would seem to be better to send a gauge as Instrumental should store an average or combination of the values.
Partly as an exercise in doing some new stuff in Go, partly as a requirement for shipping something internal.