I have two MacBook Airs, one running Catalina and one running Big Sur. The look and feel and functionality of Big Sur is markedly inferior to Big Sur, in my opinion. The graphics seem to have been dug up from the early days of GUI and I feel like most everything I try to do in Big Sur would have been easier in Catalina. I don't recommend "upgrading" to Big Sur unless absolutely necessary for some software-mandated purpose. I hope Apple endeavor to bring back the cleaner interface and functionality we enjoyed with Catalina in their next upgrade. Thanks!
