Several years ago I purchased the bucker.net domain and connected it to the free google apps offering... the bucker.com domain was taken by a domain squatter who would not take my offer; but that's another story.
Now that Google is getting serious about their hardware support and closed the free google apps product Google is trying to entice me to move over to the paid google for work. (They also cal it Chrome for work).
I use my domain for both my family and work communication. Maybe I should have more than one domain but this is no different than using my cell phone for company business. The telco has not adequately solved the multiple phone number problem so why should I solve the same email problem. I have one phone number and one email address.
There are a number of good reasons to buy into Chrome for work although I've prefer Chrome for Home or Chrome for SOHO. Remote deactivate, unlimited data, kiosk and signage features, maybe even monitoring my kids. (they have iPads too and we just configured our "family sharing" feature and it's passable for now.)
I have 3 chromebooks, 4 chromeboxes, 4 chromecasts, 1 chromeaudio, 1 chromebit and 1 android phone. Between the Chrome for work and annual device licensing I'm looking at $1130. That just seems unreasonable.