"Many suggest this default is a good way to get favourable benchmarks but there are no official ones so I don’t think that’s relevant." Sure it is. People down

"Many suggest this default is a good way to get favourable benchmarks but there are no official ones so I don’t think that’s relevant." Sure it is. People download MongoDB, run some simple workload against it, and see how fast it is. It's not an official benchmark, but it's still a strong part of the marketing message. So, if those people don't understand the significance of sync/async, they may be getting a false impression of the speed.