I've never figured out the draw. Those phones are a fucking nuisance, they are expensive, people abuse them, and why would anyone want to be on call 24/7?
I have a cheap land line I use maybe once a month to order a pizza. (Glory Days all meat NY style pizza with black olives, the best freaking pizza on earth) I maintain I'm just not important enough for a cell phone. That's my story and I'm sticking to it. Guess what? The boss doesn't call me at all times night and day, on vacation and on weekends!
And if I have an emergency, that's what my land line is for.