My experience with Plan 9 is from my first employment at Kreatel Communications and doing basic admin of the nCUBE/C-COR VOD servers that some of our customers used in production and we had for integration testing. The OS those servers ran, Transit, was apparently based on Plan 9.

Coming from a Linux and Solaris background the shell was quite basic to say the least! I remember on some instance that we for some reason wanted to bypass the web UI and hand-edit some file and the only editor available was some variant of ed...

But with a steady hand when doing such things and software upgrades etc it worked really well and was quite capable for the time (2006).