As far as my research has taught me is that Node has a huge community and is updated regularly. That plus all the recommendations here sold that for me.
All good
The same rings true for rails but my advice always is to try the one's you considered and then use which ever one feels the best to you, there's only so far research will take you with all the biased opinions out there. ie. X is faster than Y for dev time, useless fact if I end up not liking X at all.
The reason I say this is your design decisions now will impact your app for the rest of it's existence, so be completely sure what you choose is what you feel the most comfortable with and is the most cost effective (if the learning curve of Node is quick because you already know Javascript but they introduce a lot of breaking changes ...ehem, Python 2 vs 3... then is it more cost effective in the long run).
All frameworks are inherently the same, they have libraries and dependancies, talks to a database, the usual stuff. It's just how that framework is implemented and if you like the implementation.
Anyway, I like technology and all languages, there is so much out there that one can't learn everything, hence I can give my point of view.
I've almost completed my workflow document, just need to add a couple more things before I start development.
From the Agile world, don't over engineer your app, there's no way to know everything your users want/need before the apps been developed.