I love the Fairmont chain - I think it's great that they're snatching up alot of the world's historic hotels and making them into gems. I recently stayed at the Fairmont in Shanghai and had the most amazing hotel experience ever. I had a buddy tell me the same about the Savoy in London. Because of that, it's perplexing for me to rate the Fairmont in Montreal so low.
The problem isn't charm, or even the service for the most part - it's consistency. I stay at the Queen Elizabeth about 2-3 times a year while I'm doing business in Montreal, and the first couple of times I came it was great: good / clean spacious rooms with excellent service, small touches awaiting me in the room. The last couple of times have been anywhere from frustrating to plain horrible. Most recently they messed up my room reservation, and I ended up knocking on someone else's room thinking it was mine - this went on for about 20 minutes at 11PM at night after a grueling turbulence filled flight. Another time they had to move me to a smoker's floor due to another mix up (I don't smoke).
One bright note however is that the room service menu is pretty decent. I tend to work late, and their late night poutines are a god send. Gotta love Montreal!