Joe,
For the record, I didn't design Hummingbird, Willard Byrd did, and frankly, I don't recall much of any of the other three courses there, although I did play them all at various times.
As to the driving distances, there are times when I figure the average drive should probably be much shorter than it is, but some of those studies were aimed at finding out what is really happening out there for various reasons. While all are a small sample size, I would trust them over any observers anecdotes, although if I was going to err in using those stats, I would err slightly on the side of caution.
I recall doing some double fairway holes, and the exact distance (from all tees) was always a point of hot debate. I recall pulling the carry distance back from the max on one hole, and it ended up being the route nearly everyone took. Put it too far out from the tee, and I have seen them never get used, and then eliminated. Probably not surprising, and to be honest, the USGA study, literally with tee shot distances all over the map, but sort of clustered around 260, 230, 190, and so forth, pretty much matches my "anecdotal" observations over the years, with 225-230 predominating.
Design wise, all of this goes to prove what CB McDonald and most of the GA guys figured out a century or so ago - angled hazards work better than cross hazards.
As to carries, I am all for them, and believe that the option to go around is what makes them more interesting. You feel like an idiot if you try and fail, when a safe option is available, but just feel frustrated if you have to carry something and cannot do it. Next time you play that hole, your failure figures into your thinking.