I have been to a few Contemporary Art Museums and this one probably won't blow your mind but is a nice way to spend an hr especially when its free on a Wed night from 5-9pm. Basically there is 1 floor of exhibits which includes a temporary exhibit which for me was the more interesting things to look at and there is also a sculpture garden tucked away at the back of this floor which is nice to sit in on a nice sunny day. There was also a Musictheque film rolling on the bottom floor theatre which I would never had found if I didn't do a bit of exploring.
Overall, a nice small museum to see some questionable art for an hr then pop back out to see the rest of Montreal.