Also, the 1.0.3 thing is probably dragging on the numbers a bit. 1.1 would boost it a little. Not enough to get it into the top tier... but a little.
Also, for Vert.x, they seem to be only running one verticle. Which would never happen in real life.
Play could be optimized a bit... but not much. What they have is, to my mind, a fair ranking for it.
Small issues with a few of the others but nothing major. I think Go and Vert.x are the ones that would get the biggest jumps if experts looked at them. And let's be frank... does Vert.x really need a jump?
So what they have here is pretty accurate... I mean... just based on looking through the code. But Go might fare better if it used tip. And Vert.x would DEFINITELY fair better with proper worker-nonworker verticles running.