mongodb/docs — pull request #1582 by asya999 (2014-02-10 20:13:22+00:00)
Title: Fixing recommendations

nearest uses closest by ping time which is not what fastest implies.

The recommendation on increasing throughput is highly misleading - there is no way that someone can expect reduced disk I/O and increased throughput by reading from nearest secondary unless their specific problem was something extremely specific (and uncommon!)