Nice to see this thread being resurrected. I’m the original poster and can say after having lived with Discourse that we are very happy we went with this platform over Invision. Any skeptics within our organization have since been won-over.
HOWEVER, I would say that one thing we would love to see added to Discourse (somehow) is a CMS feature that would enable us to completely leave behind WordPress. Right now, we have a somewhat clunky system where half our site is on WordPress and half is on Discourse. What would be better is if there were a way to have topics display on a customized blog-style homepage, with the ability to charge for paid access that could be used to control access to specific content categories.