Gordon wrote an answer about Salomon Quest 120 Boot - Men's on November 8, 2012
Main difference is the last. The Quest 120 come in 100mm whereas the 120 Max comes in either 98 or 104. There are other differences like the liner and a larger pivot point on the 120 Max. The Quest 120 is the new version of the old Quest 12, and I guess you could say the 120 Max is the next generation.