We stayed in the Alexandre Logan in April of 2009 and my partner and I were completely enchanted. It's small--only 5 rooms. We stayed in Room 3 (pictures of all rooms on the website) which has a clawfoot tub and sink in the bedroom, a little water closet, and a small sitting room where you can watch TV and relax. The whole building is historic and in amazing condition. Simply beautiful.
Our host was amazing. He gave us great information and tips about where to eat and what to do. And he made incredible breakfasts for us--including gluten-free options for my partner.
The B&B is just blocks away from St. Catherine street, and in particular the section of that street with lots of gay bars. The location is also great because although it's in the middle of a residential area (quiet), you're only minutes away from restaurants and bars (fun).
The B&B is very gay-friendly, as is Montreal in general. We would love to go back in the summer when there is a lot more going on in the way of festivals and street fairs. When we do go back, we'll most definitely stay at the Alexandre Logan.
BTW: Some reviewers on other websites complain about their strict "rules" such as taking shoes off at the entrance. This little detail only made it feel even more like a home and it's obvious that the owners care about making it as clean, comfortable, and inviting for everyone.