Me and my girlfriend spent a month in the Unit 204.
The unit is perfect for 1 person, but might also accomodate a couple if you don't don't need a lot of bed space or to cook much. It is a studio after all.
As the listing & comments note, the unit has a veery thin wall, so expect a lot of small noises like people walking around, sinks draining, toilets flushing etc. Not a big issue for me, as I am heavy sleeper, but I can see how it could trouble someone with light sleep. The neighbours were mostly quiet, however.
There's no natural ventilation but they've just installed an AC and there's very little sunlight but it is well lit by the lamps.
The wifi worked perfectly during all my stay. That was a really important thing for me, since I had to do some work.
The location is absolutely fantastic. Right on the corner of the Mt Royal Street where there's a a cluster of nice restaurants, cafés, pubs, grocery stores etc.
The communication was excellent and the host is very gentle and responsive.
Overall, I paid about 50 CAD/night, a great cost benefit, I figure.