I have been reading about this model and in my opinion it has some very strong supporting evidence, much more than the Mesoamerica model.
But, the Heartland Model as currently expounded has some serious flaws. The geography that is mentioned in the Book of Mormon can't simply be disregarded.
If the Mississippi River is the river Sidon, then what is the Sea West? The Sea West is so prominently mentioned that it has to be identified for a model to have any credibility.
If the Heartland Model is correct, then the Mississippi is the grand candidate for the Sea West, the Great Lakes for the Sea North, the Gulf of Mexico for the Sea South and the Atlantic as the Sea East.
That makes the Ohio River a good candidate for the river Sidon, considering it's confluence with the Mississippi as the head waters of the Sidon.
I plan to work this up with the detailed geographic descriptions in the Book of Mormon in the coming weeks.
One very good reason for the Mississippi to be the Sea West is because of the extensive shipping and transporting of migrants to the unsettled parts of the Land North. The Mississippi has a large number of estuaries that could take ships west to the Rockies, north to Canada, south to the gulf, and east to the Atlantic.
More to come.
If we had no winter, the spring would not be so pleasant; if we did not sometimes taste of adversity, prosperity would not be so welcome. Anne Bradstreet
And if men come unto me I will show unto them their weakness. I give unto men weakness that they may be humble; and my grace is sufficient for all men that humble themselves before me; for if they humble themselves before me, and have faith in me, then will I make weak things become strong unto them. Ether 12:27
Yea, all things which come of the earth, in the season therof, are made for the benefit and the use of man, both to please the eye and to gladden the heart; Yea, for food and for raiment, for taste and for smell, to strengthen the body and to enliven the soul. And it pleaseth God that he hath given all these things unto man; for unto this end were they made to be used, with judgment, not to excess, neither by extortion. D&C 59:18-20