Previous discussion - http://news.ycombinator.com/item?id=2526032
Benchmarks vs Kyoto TreeDB and SQLite3 - http://leveldb.googlecode.com/svn/trunk/doc/benchmark.html (discussion - http://news.ycombinator.com/item?id=2813061)
Benchmarks vs InnoDB - http://blog.basho.com/2011/07/01/Leveling-the-Field/