However, I question who would get a Chromebox though, because the portability + battery life + instant on are no longer relevant in this case, and those were by far the biggest benefits for the Chromebook. For a little more (~400), you could get a very respectable machine running a more powerful OS.
Some general thoughts on my experiences with the Chromebook: As a general computing device, I thought it was more or less completely sufficient. I used it to take notes (google docs / evernote) in class and it was awesome for that (light and portable).
With more than 7-8 tabs, things can get slightly sluggish (read: not instantaneous). Running more than 15 or so and you start getting serious performance issues. This is less of a problem than I thought because it forces me to maintain focus (I regularly can have >100 tabs when using my desktop). Full screen 1080p video also was sluggish.
It has a shell, so you can SSH and code also.
Frequently less technical friends would ask "but ... it only runs chrome?" to which I respond "well what can you not do in chrome?" and they have a very hard time giving an example. With gmail / calendar / docs / evernote / your music web app service of choice / etc, almost everything can be done in the browser.
To be fair, I also use a powerful desktop for more intense tasks (photo editing, coding, and occasional gaming). I doubt I would use the chromebook/box as my primary computer.