I'm a new NodeBB user, and I think this plugin is fantastic! Most of my users aren't tech savvy enough to know how to write markdown, and I think that's probably true for most forums, so in my opinion this plugin is the key to getting NodeBB into widespread use. It's also a key competitive advantage over Flarum, which doesn't have a WYSIWYG editor yet, and necessary to compete with the heavyweights like XenForo and Vanilla.

It worked great for me. One thing I found is that it isn't compatible with the nodebb-plugin-imgbed plugin - I ended up with <img> tags with URLs that contained markdown inside the src attribute - but everything worked fine once I deactivated it.