Been in NJ about 17 years now after first 33 in IA. Have also traveled for work a ton, so have done several month long stints in many different locations.
Food: IA: Casey's pizza (taco pizza in general), Maid-rites, Breaded pork tenderloin
Family: Well, some of them.
Weather: Thunderstorms, being able to see the stars. Do not miss humidity in summer and long winters.
Recreation: ISU games, state parks, cheap golf
I agree with some others that the 'niceness' in IA is overrated. Surprisingly, I think NJ folks are just as welcoming if not more. Also driving, despite popular belief, NJ drivers are much better. We HAVE to be because there is so much more traffic. IA drivers act like there is no one else on the road.