Depends on your criteria, but that's a credible study.
However it does wind up leaving Texas and Wisconsin off the list, and they certainly have the reputation.
Something worth looking at is a book Dave Morris of the Bucks of Tecomate fame. I don't remember the title, though. He addresses differences in size from region to region. He had a nice map in it showing the size differences of the various subspecies and showed where they resided.
One anecdote from it: He was in Florida and spotted a huge head mount among a collection of good-sizd Florida racks. In it's ear was a tattoo'd number. It had been transplanted from Wisconsin as part of a restocking program years before. It's genetics had allowed it to get much, much bigger than what was typical even for big deer in Florida.
The other thing I liked in that book was the case he made that we ought to consider trophy antlers more in the context of where the deer was taken. A 180 point buck on his managed property in Texas is one thing. Then there's the guy who a few years ago shot a 180 point buck on public land in Massachusetts or thereabouts. that's another magnitude.