I have a late 2013 Macbook Pro. This update bricked it. I have a tendency to install most Apple releases when they are first available, even though there are often problems that are usually fixed with a few updates.

I'm sometimes able to boot into Internet Recovery mode (Command-Option-G). Unfortunately, it seems like the only option is to reinstall Big Sur, which doesn't fix the problem.

Hopefully once Apple fixes this issue, I will be able to install the updated version and get it working again. If not, this machine is 7 years old and more or less on its last legs, but I'm still somewhat disappointed.