We've been working on some Web Components that use the js sdk to talk with matrix but have been wondering if we should spend time looking at how the react sdk could be implemented in this use case assuming it would better handle encryption etc... although I think I read recently that the js sdk also handles encryption - but we'd need to add UI for verification to access encrypted rooms which seems likely to be a pain across browser sessions... there's also an issue as to which websites you might trust to share your matrix user token with to post on your behalf (but will check out Hydrogen to see how it handles this).

So thinking out loud, for a disqus clone - sticking to unencrypted rooms and web components could be the way to go! Thanks for the GSOC and Hydrogen links - will check them out!