The problem is varying expectations.

Mine are, pretty much, that you have x-term and ssh. This time, those things pretty much save my first day of vacation, because I can ssh into our production server, vim the Apache config, and restart the web server. That's something that would normally require me to at least carry my laptop with me to the beach for the 2 minutes of work, but now I can just take my N900. There's your counter-example for limitation.

For the true Unix nerds, yes, I could use at. but I do like the hands on approach and the fact that I can also fix things that go wrong (they will, every once in a while) right away.

To me, that is something that does not really lose it's value over time.