Definitely room treatment. I have more than enough gizmos that don't get used, outboard gear that looks cool & doesn't get used, mega amp that doesn't get used, instruments that get used once or twice a year. I REALLY should clear stuff out & get the room treated but a) I can't throw anything away & b) there's no room for the treatment because of the stuff (now, that's an outright lie).
Yep, treatment for the room's little audio/sonic quirks (man after playing guitar or bass in there reasonably loud for 5 mins there's a low freq hum that sits around for 10min after everything is turned off. I need treatment after that & so does the room.