The Maple Leaf Club at the Montreal airport (international side) is small, but as elegant and well kept up as the international and domestic clubs at YYZ. Maple Leaf clubs always have soup and salad (after 4:30), which is generally quite good, and always seem to have a good selection of cookies and other treats.
They also have decent free alcohol including good beer (draft Guinness) and a good selection of liquor. My preference is for the Crown Royal. The bathrooms are clean (small at YUL). There’s free “DataValet” wifi, but I couldn’t get an IP address at YUL (generally it works, but the service isn’t particularly snappy).
Star Aliance Gold gets you in, but you can also buy access with your ticket for small extra fee – something like $15, which is a lot cheaper than buying a few drinks at an airport bar. Plus free soup! Can’t go wrong with free soup.