Cell phones have saved my butt on a number of occasions (cars breaking down.)
In the case of family emergency, I need to be accessible as well.

So a cell phone is pretty much a must have at this point (1 each for my wife and I.)

The built in camera, web browsing, and push email are compelling as well.

I've had other phones with other companies. They're all pretty much the same. Some things better, some things worse. Nothing ever perfect. It's the coverage bubble that's the deciding factor.