Yes, some winters can be absolutely brutal. But like others have mentioned, you don't have to deal with drought, wildfires, hurricanes, etc. And the upper Midwest summer weather is amazing IMO.
The public transit is fine but could be leagues better. Wish the CTA would finally create the Circle Line - going to the Loop and back out to get to disparate parts of the city is so inefficient. The bus system is pretty good tho.