Not sure why you are downvoted.

One of the biggest concerns about any DB is speed of query execution. Today a decent app/site can generate terabytes of machine data that you need to analyze. There is a massive difference in usability of a query that takes < 5 secs vs even 5 minutes. So, some benchmarks of speed vs major use cases would have been ideal.

I understand, general purpose DBs can't be the best, but I can compromise for 80%. If it's 50% or less, then I really have to question that choice.