would be applied into Donationcoder.com, would that also not be to gut the whole forum section and surrender it completely to the organization/company behind the Discourse software?
Granted, that would likely take away a load of traffic and subsequent costs. And as such it might be an option to consider. Now I have no clue about the monthly stats or costs donationcoder makes, but I assume that it is between 100k and 500k monthly page views. That would require donationcoder to pay discourse 200 US Dollars a month for their 'Business' plan. Not that cheap. 2400 US Dollar a year buys a nice hosting plan with quite some bandwidth.
So you hardly save in costs, give away the control from a big part of this site to a 3rd party and introduce an extra point of breaking serving a forum that is barely an improvement on the system you already have in place and has proven itself.
Personally, I don't find Discourse to be that nice looking. Previous posters already mention other features in the Discourse system they consider to be flaws. As I don't participate with sites that use Discourse (because it is always disabled by the uMatrix plugin from my FireFox browser) I can't really tell. Yet I gladly take their words for it.
And indeed, web applications are more often than not a (p.ss) poor substitute for a desktop application. I run my own mail server and have installed a web mail interface, but only 1 person in the company actually uses this interface and only when he is not in. I simply do not have the time to waste on the daily load of mail I need to process in any web mail client.
Now there are also good experiences with web-applications. Jira is really great for issue tracking and with all the Skype problems lately, it was pleasant to know and work with MatterMost (on-premise). Heck, I would even say that using WebMin for managing (headless) Linux servers could be seen as a good thing.
Back to the point: There is hardly and benefits in using Discourse, not cost-wise, not feature-wise and you add the disadvantage of having an extra point of failure for your website's functionality. Just for the "pretty"? Now where can I sign up for such a deal...