The disadvantage of using our phones for everything is that you can't do anything else while on a call, like take a note or look up a map. And with our world rapidly converging to a place where our primary computing device is in our pocket all the time, this is going to be a problem. Maybe not a very big one, but a problem all the same. The only solution for now seems to be putting your phone on speaker and multitasking. I wonder if we can come up with anything better.
Mokalus of Borg
PS - Probably not.
PPS - Unless it involves relying more on text-based communications.