Well, I was going to vote for Mesoamerica, but since I saw my name attached it seems a bit redundant. As for other non-Sorenson models, yes there are. The main variant is those selecting the Usumacinta as their Sidon. The two benefits of that one are a more orthodox north/south orientation as well as lots of nicer ruins. For those who spend time with the Sorenson model, I suspect that a disappointment is that it can't match the sites in the Peten. Frankly, I think that is a better textual fit, but then I am kind of tied to Sorenson (with his post 1985 changes.