I tried wayland maybe a little over a year ago and the copy and paste behavior was bad enough to switch back. I recently switched to get freesync to work on multimonitor and the issue is now manageable.

app sandboxes I fell less positive about - I dislike them since I think they are only fixing stuff that is already unaceptable to happen.

As for audio - yes while pulseaudio was working i remember some issues with that (mostly related to s/pdiv). This also has lessened with pipewire.