I've only had a smartphone for about two and a half years, but I had a standalone PDA for at least five years before that (I think longer).

It's the PDA features I really couldn't live without. Being able to schedule my next hair appointment while I'm in the salon for the last one. Finding the phone number of a person or business I call frequently enough to be in my contact book, but not so frequently that I know it by memory. Adding things to a shopping list as soon as I realize I need them, and knowing the list will be there no matter when or how I get to the store.

The real choice, I think, isn't between smartphone and standalone "dumb" phone. It's between electronic management vs. carrying around a big paper book like we used to do, or multiple slips of paper that may or may not ever get re-written where they're supposed to, and that don't automatically remind us of stuff.

And yeah. Texting with a numerical keypad is a huge PITA, though predictive spelling is way better than it used to be and DH got pretty adept with it before he finally got his iPhone.