Ask HN: Event loop vs. Threads

Hello, At my work place we have a lot of legacy C++ code that uses threads to parallelize things. We are considering to switch to Node.js and searching for sources comparing the Event loop model vs. a threads based one from perspectives such as the following: efficiency, ease of maintenance, etc. Would be thankful for any references to good constructive material.

EDIT: more details about the application - it is a trading app that communicates with multiple sources at high rates to gather information and send commands, but it also does quite alot of number crunching.