There are 2 ways to look at this. Just for living purposes, Des Moines or should I say the Western burbs are a great place to live. The rest of Des Moines is a dump. There is much less traffic obviously in Des Moines and the cost of living muck less expensive.
Professionally, it's a different story. Minneapolis, as mentioned by someone else, has several F500 companies. Des Moines has The Principal Financial Group. I spent 10 years there. Good company but a little bit cultish. Minneapolis wins the professional aspect easily.
I'm an Iowa native, but Minneapolis has some great things Des Moines will only ever dream about.