JC,
I think it is good to have a mix of contours that are to be used and to be avoided, but holes that incorporate contour utilization are much more interesting. One of the things that was so fun about Prestwick was the set of greens were contour utilization was at a premium. Many of those contours are random or pre-existing around these greens, but, as Don Mahaffey points out, these contours can often be used as backboards and sideboards to get the ball close from around the green or on an approach shot. When at Prestwick, I spent at least 20 minutes each around the 15th, 16th, and 17th greens, experimenting with different clubs and shots off the usable contours. Of course, each of these greens had contours to be avoided, but these were only effective because they combined with contours that could be utilized.
Contour utilization allows for more creativity, variety, and, most importantly, pure fun, especially around the greens.