The best 'self-contained' video conference machine I've used in the last year is:
1. $400 less up front than the Chromebox
2. Has an annual service fee $200 less than the Chromebox
3. Has a camera with awesome built in face detection (if one person is in the room it centers on their face, if three people are in it automatically expands to fit them all in, if you wander around the room it follows + refocuses on your face).
4. Is voice controlled.
5. Plays Lego Marvel Superheroes at 1080p.
The XBox One and their Skype integration is really well thought out and solves most of the annoyances surrounding video conferencing, focal length, bad speakerphone mics, etc. highly recommended.
Once you've got that, Skype's screen sharing leaves a bit to be desired. Hangouts allows for screen sharing of individual app windows, which I consistently miss when using Skype.
Additionally, Skype video calls under the premium plan have a fair use policy with a limit of 4 hours per session with a monthly cap of 100 hours total. That may be okay for an individual, but is probably not the best solution for something sitting in a conference room shared across a company.
Of course, it's also a matter of business models and how each company earns its revenue. However as the end user, "free" is better than $x/month
It's a fine point, but it might matter to some users.
Also, for collaborative document editing, I think Hangouts are going to win, hands-down.