Where do you see people out in Chicago at 4am? The sidewalks of Chicago are pretty much empty after 8pm. Places like the Loop and Michigan Avenue are crowded during the day but once the sun goes down, it's like a ghost town. Even a nightlife area like Boystown, is pretty quiet at night. When I was in Chicago a few years ago, I went to a different bar in Boystown & Andersonville, every night of the week, for 10 straight (or in this case, gay) days in a row. Even on weekends, it felt deserted. Church Street in Toronto is so much more animated and lively.
I've been to Chicago on numerous occasions and I still haven't found an area that's lively at night. People in Chicago tell me to go to Wicker Park but I don't see anything interesting or lively about it. It's nothing like Queen West, The Distillery or Kensington. Those places have character but Wicker Park just seems like any other bland, ordinary part of Chicago. I think Old Town is much nicer, with better buildings and restaurants but again, it's pretty quiet at night.
On thing Canada does right is cities. We may not have many big cities but all of our big cities (Toronto, Montreal & Vancouver) have a lively, cool street vibe, day and night. The only American city that has a better street vibe at night is New York City. Toronto, Montreal and Vancouver are great places to walk at night. They all feel safe, are lively and interesting to walk around. Toronto's animated area keeps expanding year after year and the sidewalks become more crowded too. It's a really exciting time to be a Torontonian. We have so many interesting areas with the population density exploding and street life developing. You can't really say that about Chicago. I've been going there for years and I don't notice new animated areas or more people walking around. (especially at night)
Oh, and another thing, Torontonians are much more eccentric, exotic and interesting. You do not see freaks, hippies, punks, queers and the quirky mix of people we see every day in Toronto. The people of Chicago look much more conservative/conventional than Torontonins. I noticed that on my very first trip to Chicago. Toronto really has a large number of quirky, eccentric, distinctive people who live here and are not afraid to let their freak flag fly. I think people just feel more free to be different in places like Toronto and Montreal.