My best friend played in the US MIDAM at the Cassique and absolutely loved it. He is very well traveled and felt like the Cassique was such a great blend of options and strategy but very difficult and still fair. I have found that to be a rare combination.
The only Tom Watson course I've played is his National course in KC. I sometimes like to play hard courses, and it was definitely that, as well as in great condition, however, I felt like the property was a little average. It is not a walking course and although I very much enjoyed it, I didn't see anything really unique.