I've set up a Synology NAS in my home network last week. One of the reasons was that I want to run a node server, and Synology offers it out of the box with DSM 5.2.
Because I want to check out / make use of ES6 features I had to find out which versions of Node and V8 are coming with the package. This is how I did it on the SSH shell:
Fortunately there is a discussion on StackOverflow which answers which features node has enabled by default and which can optionally be enabled using the --harmony flag.