Hi JJ,
I was planning a trip of my own a couple of years ago, and ultimately spent three months on the road looking at several different golf courses. So much of this is dependent on how long your trip is. If it's short, I'd try to see as many good courses as you can. It's largely because this website has become an incredible resource for seeing some of the lesser known tracks through photographs and profiles. But ultimately much of the conversation revolves around the better golf courses, and seeing not only what works, but what works brilliantly, is incredibly insightful.
That being said, if you have a longer trip planned, I'd absolutely check out the "mediocre" courses. I found that the places I learned a lot from had a few holes which were quite good but were dominated by otherwise bland holes. The reasons for this were extensive and often varied, and while I may have picked up more smaller details at some of the great courses, it was these courses which developed the more general, big picture ideas the best (For example, the club I caddied at back in the day, Claremont CC, dealt with several issues of it being a small property through several crossing holes and a few shorter, narrow par 4's. As space becomes more scarce, it made me wonder how such problems will be addressed in the future. It's a discussion I still have with myself.)