Since the release of mongodb-native driver 3.0.3 the driver got increadibly slow. I am also recommending people to use the 3.0.2 driver, if they care of performance and their implementation works correct with the old driver.

In my opinion, mongodb could be a magnitude faster on the node-platform and is currently just so much slower. In my opinion it would be a good move, if mongodb team considers to hire some external dev to support/write an incredible fast bson package. I am thinking about marcj or kriszyp (nicknames from github).

Tbh. kriszyp wrote very fast implementations of cbor and msgpack, and I think he would be able to support mongodb to write a super performant and fast bson serializer/deserializer. Even considering to not use typescript to ensure, that the performance of the serializer/deserializer is high, should be a valid option.

See here:
https://github.com/kriszyp/cbor-x

I am not affiliated with them.

I think, if you hire one of them for the rewrite you would help the whole node and mongodb community by supplying the fastest bson implementation.