I stopped by Reuben's to eat today as I had relatives visiting and it's one of their favourite restaurants. There are two locations in Montreal. I do not believe that they are affiliated, but this one is much nicer. It's always very clean and the service is always excellent. You can tell that the servers are trained very well. During the evenings (especially on weekends), I would suggest making a reservation because the wait times can be pretty long if you have a bigger party. There's also rarely parking on rue Sainte-Catherine, so I would suggest walking.
My only issue with this restaurant is the lack of options for vegetarians and vegans. Even most of their salads aren't vegetarian. Obviously I don't expect them to have a menu accommodating such requests, but an option or two would be a good idea for people like me who end up having to pay around $20.00 for a salad after removing half of the ingredients. Although pricey, the menu is awesome for those without any sort of restrictions. And from the looks of everyone's meals, you seem to get what you pay for.
I would definitely recommend this restaurant to any non-restrictive eater looking for a nice place to go. You won't be disappointed!