Both cities are amazing with very different things to offer. Of course it all comes down to what kind of lifestyle you prefer and what's important to you. Here's my take:
Montréal is reminiscent of Europe with the architecture and general culture. By no means a flat, grid based city like Toronto, streets are often curved, angular and uphill or downhill depending on your direction. Makes it very charming. The way of life is much slower and relaxed compared to Toronto. People are out and about having fun and simply enjoying life. Not knowing any French can be a hindrance but you'll get by. There will definitely be times you will encounter a language barrier but that's all part of the experience. It's not as sprawling but that's also part of the charm.
Transit is good enough, food, bars, clubs, all great. Mount Royal is beautiful in summer as are all of the parks. Winter is generally harsh. Healthcare is a big issue, I can speak from experience that hospital service is lackluster and inefficient. Knowing French is an asset in this case. Many people have an issue with the language and fail to grasp or understand the culture. There can be a palpable disconnect between Anglo residents and French speakers but it all comes down to perspective. Some people can live there for years without knowing French and get by just fine.
Toronto is vast and dense. Modern but also a concrete jungle. There are tons of different neighbourhoods each with their own appeal. Chinatown, little Italy and Portugal, little India, Greek town, Korea town etc. Extremely diverse and tolerant city. I don't care for comparisons to the US, while you can see the commercial influence, the attitude of people is very different. The cultural diversity and general open mindedness of people is truly incredible. Transit on the surface appears to be okay, but the city has grown so rapidly that the infrastructure can't keep up. Everyone complains about traffic and transit.
Food is unbelievably good. There is an air of pretentiousness in the city. Lots of niche, underground scenes. People care very much about identity and like to exude a specific look. Cell phone culture is obnoxious, everyone is tethered to their phones. Nature wise, Niagara is relatively close, cottage country is really accessible, though there are no real impressive parks in the city. Lastly, it's expensive. Cost of living is much higher than Montréal. Much higher. Big one to keep in mind.
Both cities are of extreme weather. Hot muggy and humid in summer. Frigid and downright bone chilling in winter. I could go on and on but hopefully that paints a better picture OP. I've lived in both cities and love both equally.
The crazy ones probably eat it once every weeks at the minimum.