Pros:
The hosts were very helpful and quick to respond whenever I needed anything but without being intrusive. Definitely 5/5 for them.
The apartment is quite large, in good condition, and adequately furnished with almost everything you could need, including some food. The washer and dryer are actually in the apartment and not just shared "on the premises" like in some AirBnBs. Overall, I thought the apartment was very good value for money by Toronto standards.
The location is quite near a subway station and within walking distance of a supermarket and pharmacy. However, it is a very suburban area that seems very much designed for cars, so while you'll have everything you absolutely need nearby, there's not much more than that, and you'll have to travel elsewhere or walk quite a few blocks if you want to visit restaurants, etc.
The Internet was extremely fast and stable - among the best I've had at an AirBnB.
The cons:
The apartment is very cold, even compared to other places in Toronto in winter. There's no way for you as the guest to control the temperature. I did ask them to turn it up once, and they did, but it didn't help a lot. There's also virtually no natural light since it's a basement apartment, which doesn't help the cold.
The neighbourhood itself is quiet, but since this is, again, a basement apartment, there can be a lot of noise from upstairs. It's not that the hosts are exceptionally noisy people, but you can hear footsteps and sometimes voices very clearly since you're right underneath. There's a dog that spent a whole afternoon barking and whining, for example, and I was awakened at 4 AM one morning by someone walking back and forth repeatedly over the bedroom. These problems aren't incredibly frequent, but they are something to consider if you're sensitive about noise.
All told, I would recommend the place as long as you're not too picky about location or noise and either don't mind the cold or plan to visit in a warmer season.