I've stayed at neither but they are where I will stay on the next trip to Montreal; hotels are equivalent though quite different (starkly so!). St. James is larger, more traditional, in a beautiful old building (really outstanding architecture) and is an LHW which probably has the highest standards of any chain. Gault is more modern and has won many design awards. Montreal hotels have improved by an order of magnitude with the opening of these 2 hotels. Doubt you will find anyone who has stayed at both -- they are too new and if as good as they seem to be there would be no reason to stay elsewhere. I'll pick based on availability and value; in my judgement these hotels are equivalent, and far better than anything else in Montreal.

You might be interested from the following comparison of these 2 hotels that I saved when I was researching where to stay in Montreal:

"The most sumptuous is the Hotel Le St-James, which was fashioned out of a 130-year-old merchant-bank building in the Old Montreal district. Travelers looking for suites with antique furniture and plasma-screen-TV-equipped, marble-encased bathrooms can alight here for $300 to $3,750 a night. A bit pricey, non? "Our guests don't ask the price, they ask for the square footage," sniffs the hotel's directeur-general Guy Luzy. If price does matter, try the Hotel Gault (514-904-1616), a minimalist gem where classic 20th century fixtures and furniture are set against bare white, oak or hot-rolled-steel walls and concrete floors. Tucked away on a quiet Old Montreal street, the Gault's design aesthetic is so gaunt that a visitor can barely make out the insignia by the front door. Rooms are $170 to $435."

Thanks number_6, I'm in agreement with you from the research I'd done as well. I'm opting for the St. James and I'll advise after, hope you will too.

I am holding a reservation for three nights at Hotel Gault for our 10th anniversary. TripAdvisor has Gault rated #1. I usually agree with their results but will revisit this issue. Any concurrences with the above findings? Any recent stays at either or both properties? Recommendations? Thanks!

I am staying at the Gault this coming Thurs-Sunday and very much looking forward to it. I'll post afterwards.

Just got back from 2 nights at the St. James. While it's a very nice property I don't think the value is there at the price. Junior suites go for about $500 US per night and they are not large, in fact, it was no bigger than some regular rooms at other hotels I've stayed at. Also, the windows looked directly into the office building next door, so the curtains had to be closed at all times making it very dark. The breakfast buffet was the only meal I ate in-house and it was underwhelming. At $25 per person, the buffet items (cheese and meats particularily) should be perfectly fresh. They didn't look it. The croissants looked great, but they are the size of a football which is a little off-putting.

The staff/service was as good as anywhere I've stayed with everyone taking responsibility for the guest at every level--it certainly creates a feeling of being cared for. Hwever, one expects that at any top tier property and is not enough to justify the price.

Although it is a very nice property, unless I can get it for less than $300 I think I'll stay elsewhere.

I’d be curious how opinions have evolved on this in the last 17 years. What are the best hotels in Montreal nowadays?

There are a couple of threads on this topic in the Luxury Hotels forum. Might want to take a look over there.