Have you found any hidden feature in the macOS BigSur update? Mine is, Now you hear a sound on opening the lid of Macbook Pro on first boot.I like the two horizontal bars at the top right of the desktop, and the overall design is better IMHO. What I really dislike is the strange behavior of the Calendar app. It came up with its notifications on upcoming holidays repeating every 15 minutes. The issue somehow dissolved itself before I took any action.
Also, I was unhappy with Safari redirects in CATALINA. As an experimental solution to avoid such issues in Big Sur, I have downloaded BRAVE browser (installed it in BigSur) as advised at another forum. The browser was installed with its start page set to SearchMarquis.com and I cannot remove Brave browser. I suspect it keeps its processes running and NAMED in such a WAY that they cannot be attributed to Brave. I see other users are also experiencing this problem...
https://discussions.apple.com/thread/8475541
I am very annoyed with that and gonna take action
P.S. Just have found out that Search Marquis is considered a virus, there are plenty of descriptions like this: https://macsecurity.net/view/289-search-marquis-com