It's great docked, except for an audio bug in Linux that causes some occasional minor (but annoying and concentration-breaking) static sounds while outputting over HDMI. It comes and goes on its own.
The bug is acknowledged by Valve, and it's (to the best of my understanding) not something specific to the Steam Deck. Supposedly it's being worked on, but no fix yet.
Once fixed, the Deck will be nearly perfect in my eyes.