"A little in between hit and miss"
Aside from the beautiful pictures you can take of this place, there is much more that could be added to make it a better experience (this is coming from a biomedical scientist). The latest fashion exhibit (October 2015) was kind of interesting because glamour gowns were created from things that we normally would discard (plastic bags, fish skin, hair, etc. ). The views from the top of the museum are nice, especially when the leaves are turning orange. This place would be great for the kiddies, since there were lot of interactive things to do. There is even an interactive microbiology lab. But, many older folks probably only would enjoy the structure of the building's "exoskeleton" and the views of Montreal.
If this is your first time visiting Montreal, I would put this at the bottom of the list unless you really want to go. Since this was my second trip, I did not mind so much.