In my experience the main issue with the M1+macOS experience is not the ISA, it's the big-little thread scheduling. I'm not sure what they were thinking but there's some heuristic that schedules background or batch work on the little cores. This includes manually-triggered software updates which unfortunately can take forever on those little cores. I waited almost 4 hours for an Xcode update to complete. All four little cores were maxed out the whole time, and these new chips only have two of them.