I went to Complexe Desjardins since this shopping mall/complex houses the main office of Revenue Quebec in Montreal and I needed to pick up some tax forms.
The mall is very large and even though it was built a long time ago (probably over 40 years ago), it is very well maintained. It has clothing boutiques and a food court. There is also a main atrium area that will sometimes have special events with various water fountains. It is connected via underground tunnels to both Place-des-Arts as well as the Place-des-Arts metro station.
The only time I will find myself in Complexe Desjardins is either I'm on my way to/from Chinatown and I'm on the green metro line or want to be on the green line or I need to go to Revenue Quebec. Otherwise, I will just walk over to the orange metro line (Place D'Armes metro station) when I go to/from Chinatown.
Although I don't go to Complexe Desjardins often, I find this shopping mall/complex to be well maintained and I've never had any issues here.