Oh dear, he asks a bunch of devs on opinions! Good luck with that spam :)
On topic, one of the great things with Node is not so much technical gains, as business value. With Node.js and tools, you can make practically hourly changes. You can assemble, test and deploy a, say, new dashboard in a day and ship it to production. You (in most cases) can't do that with Java, the whole cycle is much much slower.
So on the business terms, Node.js is much faster and allows for very fast iterations. I think this is important in two groups of users: startups: they will have many changes in the product design as they grow. Node is not very rigid and allows for this. Corporate users: at least the leaders there. They are getting sick of clumsy big Java pipelines and expensive IT, as they want results fast. So this is a way to get something out there without disturbing anything "important" in the core transactional systems.
That's my two cents after a sleepless night, so don't mind me :)