Hey Toronto3,
Steveve's thoughts are in line with mine regarding Chicago. Here are a few more: In addition to Chicago's skyline being substantially bigger, with more iconic buildings from almost all periods of architectural 'themes', its waterfront area blows ours away (even after taking into account the future developments Toronto will see over the next decade or two), the designs of many of the condo buildings, especially the newer ones, are more aesthetically appealing than ours (as they have less grey buildings and use less spandrel than Toronto's condos); Chicago's roads are more grand and boulevard-like, the quality of the sidewalks and roads are better (with fewer potholes and patches) and many of them in the 'greater downtown area' are wider too (than ours). Its shopping options are better, and thankfully, Chicago also has a lot of ethnic neighborhoods (just like Toronto) so if you're the cosmopolitan type, you wouldn't miss out on the variety of all things global.
Further, its mass rapid transit system is significantly bigger than ours with eight real lines (i.e. not something like the Sheppard stubway or the Scarborough RT system), and both of the city's main airports (O' Hare and Midway) have connections to these local train lines! As much as I like streetcars, I find it a nuisance to use them for actually going from one place to another (especially on Friday and Saturday evenings) as they're slower and block traffic, etc., so the fact that Chicago does NOT have streetcars is a plus for me!
The customer service and social skills of people in general is far better in Chicago (as it's an American city after all) and hence you won't get as much of the reserved Canadian mindset; as well, a higher % of the Canadian population cannot communicate effectively in English compared to their American counterparts.
Finally, since I'm a gay male, I find the gay nabe of Chicago better than ours; first off, it's visually more appealing; second, it has more variety/options in terms of lounges, bars and nightclubs. Chicago's gay nabe has five full fledged and nice gay dance clubs, unlike Toronto, which has two (Fly and Straight). The Barn and Buddies don't count as '1st tier clubs' as they're too rundown (but that's of course my opinion).
Now, Chicago also has its disadvantages compared to Toronto like the crime rate, deeper racial segregation, and a weaker economic situation (at least for the last few years and most likely the next few years). Note, Chicago's economic base is really diverse and the metro area is home to many headoffices, just like Toronto. We also cannot forget the other typical US-Canadian differences, like health care, gay rights, etc. (for which Toronto has an advantage over Chicago).
Overall, both cities are comparable in quality of life but it's just that as a gay male who is into urban development and design, especially in the main parts of the city (I don't care much about the suburbs), Chicago, to me, seems materially ahead of Toronto.
I think this is it from my end as this is the Trump tower thread after all, and don't want to deviate from that anymore.
Cheers.