Unless you need to get out of the city, public transportation is very very good.
Really? I know lots of people who don't own a car & many, many people who have never had a drivers license. Its clearly not as car free as NYC, but is anyplace in the USA?
I think one thing about Chicago is that there is a lot of variance in peoples experience. Living in Morgan Park is different than Lincoln Park which is different than Orland Park.
Lots of people in Chicago --- in the city proper --- don't have cars.
If you live in the suburbs of Chicago, you'll have a car.
Chicago has a well-diversified economy, so it's not dominated by any one industry or company. There are a ton of bigcorp jobs, but they're more likely to be for companies like Hyatt, Walgreens, McDonalds, United, Allstate, etc. Legal and finance (particularly quantitative & algorithmic trading) are big as well.
We had: Motorola (before all the splits), Lucent, Westel, Telabs, USR, 3Com and more I'm probably forgetting.
People will decry the violence (of which the vast majority is confined to the disadvantaged parts of the city[3]) and the weather (which you get used to and should stop being a wimp about), but I find the salary / cost of living ratio far outweighs the disadvantages.
[1] https://www.thrillist.com/lifestyle/chicago/the-l-rent-map-w...
[2] http://www.chicagotribune.com/news/local/breaking/ct-bicycli...
[3] http://crime.chicagotribune.com/chicago/homicides