The problem we have in general is that the REM should have been expanded way beyond the Montreal suburbs. All the planning for public transit is controlled by local agencies and no larger integration vision. I have a family member that now has a longer commute because the bus go to the REM instead of straight to downtown Montreal.
It's also super useless if you live a bit further out than the immediate Montreal suburb like I do since you already have to take your car to the highway so it is faster to continue driving on the island vs getting out, finding a parking, waiting for the train, etc.
Personnaly I am very critical of how we handle public transit here vs what I saw can be done in Europe.