json parsing performance

[Kingsley via Digitalmars-d]

I have read that std.json is pretty slow compared to other 
languages json parsers and I'm about to do a whole stack of json 
parsing and was wondering if anyone has got any benchmarks to 
indicate what "slow" means compared to other languages - 
particularly java, ruby, python?

I want to know whether to roll up the sleeves and write my own 
json parser focused on performance or if slow just means a few ms 
slower - which I could live with.