While troubleshooting it would be really handy to have a tool like:
$ riak-admin reset-all-counters
to quickly set to zero all $ riak-admin status and/or $ riak-repl status counters
This functionality is now implemented (albeit slightly differently) in the Exometer stats version, #448 and corresponding riak_kv PR #748. Even histograms can be reset, in fact. Whether that's a good thing, I guess depends on your needs.