This software kinda sucks. I guess you get what you pay for, sometimes.
Nice example of the application of recent NLP thesis topics to parsing problems, though. Quite suitable as documentation and reference for, e.g. future work on SpaCy - which is much more usable in productive contexts.
However, speed wise, its only slow in my experience, if you try to integrate via a shell script - if you run it as a service and make http calls it's been amazingly fast in my usage.
I believe they include a "service" mode as part of the package now, but for a project a little while ago I forked & extended a project that provides a JSON/XML http service: https://github.com/Koalephant/StanfordCoreNLPHTTPServer