Pat:
It's a good question. I think you can make plenty of informed and interesting judgements about a course and its architecture after even just walking it once. I do that plenty, and have posted various photo threads here having walked a course just once. Before I do so, however, I read up on the course, search this site for information about it, look at pictures, and talk to other folks about the course.
Playing a course, and repeated plays, certainly, enhances one's views on it, revealing nuances and lines of play that might not otherwise be seen on a first go-around. But I also think our own abilities, and the way we approach a course, bias (not necessarily in a bad way, but it's a bias nonetheless) our views of courses and their architecture.