I don't know if you are aware but the Chateau Frontenac has been renovated recently. I didn't visit but the pictures seem nice.

I'm from Quebec city and I can tell you that le Germain Dominion, Auberge St Antoine and le Chateau Frontenac are all good choices. However, if it's your first time I think you should go for the gold floor at le Chateau Frontenac

I now live in Montreal, but before living here I stayed on the Gold floor at the Queen Elizabeth for a couple of years and then I stayed at the W for a couple of years (a couple of week ends per year).

My first choice in Montreal would be the W (I have to say that I'm also their target market), if you have the budget for a wow suite, go for it.

My second choice would be the Ritz (the only 5 diamonds in the province of Quebec), the hotel is nice, the service seems really good. The St James seems too uptight for my taste, but maybe that's just me.

The gold floor is also a good choice, however, apart from the gold floor, the hotel is really ordinary.

Hope this helps.