For any watch brand, there'll be models that are more favoured and others that are "neglected". For Lange, this happen to be their automatic line. Historically, Lange is famous for their manual calibres, and I guess that explains the slightly lack of enthusiasm to their automatic watches. The same can be said of their Langematik line. I had one of those and I can tell you the quality is top notch, and Lange would not compromise anything in any of their models. The other reason why the Saxonia annual calendar have a "colder" reception is that it's a relative new model and not many have gone around yet.
I guess what matters most is what YOU love. If you are in love with the Saxonia AC, there's no reason to get a L1 MP or another model that you are less passionate about, just because the AC doesn't get the same attention as the other models. Personally, I think the Saxonia AC is gorgeous yet competitively priced.