Technically, I am not the best person to judge but I'd say the discourse is well developed and powered by a great community of developers. But but but.
I switched from Discourse to Flarum community software.
The reason being very simple and straight forward - Discourse is resource hungry software and needs a huge physical memory to run.
Whereas Flarum is comparatively low powered, and low memory application which barely spikes my memory usage.
I used discourse for a year and a half, and my server bill was almost doubled after installation.
Currently, Flarum running on the same server has WordPress had a very minimal impact on any server hardware usage.
Flarum is smooth compared to Discourse forum.