Concurrency and parallelism are rich concepts that have enjoyed rigorous study and debate. When an application architecture is designed to favor threads, events, or some hybrid, it is likely that the architects are opinionated about both concepts. You are encouraged to dip a toe into the theory and read the following articles. A clear understanding of precisely what the debate is about will provide an objective framework that can be used to qualify a decision to choose (or not choose) Node.
Some numbers:
https://cs.uwaterloo.ca/~brecht/papers/getpaper.php?file=eurosys-2007.pdf
Threads are a bad idea:
http://www.cs.sfu.ca/~vaughan/teaching/431/papers/ousterhout-threads-usenix96.pdf
Events are a bad idea:
http://static.usenix.org/events/hotos03/tech/full_papers/vonbehren/vonbehren.pdf
How about together?
http://repository.upenn.edu/cgi/viewcontent.cgi?article=1391&context=cis_papers
It's a false dichotomy: