I reject the word "severe" as it is applied to any of the courses mentioned.
Here is the definition of the word from the Random House Unabridged.
1. harsh; unnecessarily extreme: severe criticism; severe laws.
2. serious or stern in manner or appearance: a severe face.
3. grave; critical: a severe illness.
4. rigidly restrained in style, taste, manner, etc.; simple, plain, or austere.
5. causing discomfort or distress by extreme character or conditions, as weather, cold, or heat; unpleasantly violent, as rain or wind, or a blow or shock.
6. difficult to endure, perform, fulfill, etc.: a severe test of his powers.
7. rigidly exact, accurate, or methodical: severe standards.
Maybe #6 comes close to applying but the word severe was hardly at the top of my mind when I saw the greens at Crystal Downs, Prairie Dunes, Winged Foot, Lost Dunes, Kingsley CLub and Ballyneal.
I was thinking more along the lines of fun, interesting, challenging, hard, perplexing, wild, unique, etc...