I must admit Big Sur performs much smoother and looks neater than Catalina. I like the upper toolbar with shortcuts to essentials like wi-fi and sound control.
What I do not like is the Calendar notifications telling me of the holiday ahead. It may repeat every 15 minutes. I would rather remove the app altogether.
The issue in audio DWS still dragging their feet on the new M1 software releases! I guess developers can’t afford even a Mac Mini M1 to compile in X-Code where they could make an iPad app with little translation needed in modern X-Code!