Interesting thread! I have played both courses. And, I have played both courses with guys who know the game, golf courses, and Florida courses pretty well. That doesn't make me a genius, that's for sure, but I have my opinions and have discussed them with some other well-traveled players who love good courses and played collegiate golf in the state. I was also lucky to visit Calusa a couple times during the construction phase.
In my opinion, Calusa is not as good as Seminole. Seminole just fits the land too well, and has so many good strategic holes and shots. The site is just by far better. However, Calusa really is a great golf course. It just happens to be much more manufactured. For anyone to say that other courses in Naples are better, especially when they have not played it, is very surprising to me.
Calusa's greens are pretty interesting, and I think quite good, particularly for Florida greens. They do not have predictable contours like so many Florida courses. Unfortunately, because the land is so flat naturally, they do not feel natural or lay of the land as compared to Seminole. But, with that said, they are very challenging and fun, and do look pretty natural most of the time.
We took a trip a couple years ago with 8 guys and played both, and everyone loved both courses, but the consensus was, especially with the guys who had seen lots of top 100 courses, that Seminole was a bit better.