I think it completely depends on how you work. I have no need whatsoever for a smartphone. I only have a dumbphone to use in emergency, or so my kids can call me when we are out on the road. I just want to to be a phone.
But I do all that other stuff -- web, internet, check campgrounds, trip planning, on and on. More hours in the day than I care to admit. I just prefer the bigger screen and keyboard of a real computer. So I use a Verizon hotspot, which accomplishes the same thing as your smartphones, and the cost is similar.
So...it depends!
