Update
Was at YUL this evening, and had several hours to kill. So, I decided to see if they would let me in (my earlier posts explain my situation). I was told by the agent that a RCC member flying on US, UA, or AC is allowed entry with 1 guest.
I don't know whether this was correct or not, but the bottom line is that the agent let me and my wife in.
Anyway, we were REALLY impressed with this club. I normally am in US Airways Clubs and RCCs; I had never been in a MLL before, and there really is no comparison. First of all, the free booze is great. ^ Second, they had a really nice spread of fruits, cookies, and cold cuts. In US/UA clubs, you're lucky to find some fruit and maybe a mini-muffin, and you have to pay for booze. Third, really nice wide array of newspapers and magazines. And, fourth, computers with free Internet access.
In the two hours we spent there, I got really spoiled.
The only thing that I found odd was that the place was empty. We were there from about 5:30 to 7:30 tonight, and only one other person came in that entire time.