Yeah, same here. I am using 2012 rMBP and usually upgrade OS and update quickly after release. No significant issues with the machine. It is still chugging along on Catalina. Only issue in last 10 years was replacing battery once.
But I am waiting for Mx version of 15”+ MBP to upgrade, just need more storage and memory at this point for heavy duty work.
I suspect that some of these cases of slowdown are a result of something getting messed up in the update or some non-standard process that is getting bogged down on Big Sur.
Yeah. Same boat, mine (15" with dGPU, base spec) just keeps chugging. Never felt like an OS update affected it negatively. I've often wondered if it has to do with the Crystal Well L4 cache they put on these machines.
But I am waiting for Mx version of 15”+ MBP to upgrade, just need more storage and memory at this point for heavy duty work.