An AMS is useful just so you can have 4 different filaments ready to go at any time. Doesn't need to be for multi material models. I have an A1 with the AMS lite and a Prusa mk3s, and manually changing materials is a chore.

Fair point, I don't print enough (nevermind change material often enough) that it's such a bother that I thought of it. I expected the argument to be keeping it dry, to which I'd have said a drybox and/or dehumidifier is better and (could be) cheaper.