This is the second Sonder property I've stayed at and the unit itself was definitely an improvement over Sonder Le Guerin. The space is large with a well-stocked kitchen and bathroom. The furniture felt a bit dated and old, but my guess is that units vary greatly. It definitely didn't feel like the photos listed here.
I didn't love the location personally as it felt very sterile and corporate, with not much to do beyond site seeing and visiting overpriced shops, but this was more of a personal preference. I can see how Old Montreal would be very appealing to certain tourists, but if you're looking to see a more authentic Montreal, this is not the place to stay.
I probably wouldn't stay here again but that is more related to the location than the property. The unit itself felt good and serviceable for the most part - nothing amazing about it though.