I can't understand the argument that Mumble is functionally better. I used Vent/TS/Mumble/Skype for years while playing WoW and within 2 minutes of downloading Discord it clearly blew all of them out of the water. Joining a new server was frictionless, channels and settings were clear and understandable. It combined everything from those 4 services into 1 and did it better. I wouldn't call that "frilly features" it's just a flat out superior product.