I wouldn't go back to a smartphone.
I get 1 week battery life.
I can browse the web on opera mini over Edge network and its really fast (ok, the experience is limited, but its fine for reading the news and you get an instantaneuos back buton page load...)
I can do email facebook, irc via jar apps in an emergency.
Maps are challenging but if im really lost and have some adress reference i can find my way.
I get no distractions with notifications or app updates or any of that crap (yes i know you can turn them off on any smartphone...but do you?)
It fits in my pocket and doesnt feel like a slab when i sit down.
The only downside i can think of is that in 2 years ive lost 3 chargers... it takes so many days to drain the battery sometimes that i loose my chargers when i go on holidays or on house cleanups...