I modified the bson_benchmark.rb file to work with the new BSON class interface and ran the benchmark. It fails on the last trial.

case {"this"=>5, "is"=>

{"a"=>true}, "big"=>[true, 5.5], "object"=>nil}
enc bson
took: 30.6319999694824
dec bson
took: 57.5120000839233
expected: {"this"=>5, "is"=>{"a"=>true}

, "big"=>[true, 5.5], "object"=>nil}
got: {"this"=>5, "is"=>

{"a"=>true}

, "big"=>[true, 5], "object"=>nil}

Note that the embedded array should contain 5.5 but the decode came back as an integer.