The category you're shopping, what I call "fitness hybrids" is HUGE. Meaning, nearly every manufacturer has a bike in this category. Bikes are generally not like cars where components are specific to the brand. Treks and Specializeds and Giants (and others) will all have a mix of Shimano, SRAM, Suntour, and FSA drivetrain components (maybe Sunrace and Microshift in there, too), and it's all generally good stuff. You don't really see "reliability ratings" or "reviews" of bikes like you might cars or riding mowers because the components are pretty much picked from parts bins and bolted onto frames. The fit and finish of the overall bike is what will differ the most between brands. And, by that, I don't mean "quality", but literally fit (how your body fits the bike) and finish (colors, satin vs gloss, etc).

If you're commuting (and in Canada, where you may regularly encounter a lot of mixed weather, I'd probably go for disc brakes -- they'll be more effective in wet weather than rim brakes. If almost all of your riding is in dry conditions, then disc brakes won't change your ride dramatically. Otherwise, I would test ride as many as you can and get a feel for what you like. In this category, the Giant Escape and Trek FX ride very differently to me. I don't know what it is about them. They're using the same basic components, but something about the geometry is different. And that's my point about fit and finish -- two bikes with identical spec sheets can feel totally differently when you're strapped on.

All of those brands you're considering are good brands. They use quality components and the frames are built well. I'd let bike fit and personal preferences like style and color be your primary factors. If you like a blue Sirrus, then buy it -- the green Trek that you don't really like the color of isn't going to be a "better" bike.

Welcome to the forum!