I agree COMPLETELY that Common Ground is a great model for creating interesting golf courses where terrain or budget constraints exist.
But just because it is noteworthy in that area, does it make it a great course? When you are talking about Doak 7's, you are talking about some great courses, some that have hosted majors like Medinah #3, Cherry Hills, Troon, Pasatiempo, Spyglass, Machrihanish, Saucon Valley, Plainfield (wow, Tom needs to revisit that...), etc.
To argue that Common Ground, for all its worth, belongs in that category of courses seems like hype to me having played the course.
Doak scale is unique in that it is a bell curve. There are very few 10's, few more 9's, and keeps increasing logarithmically until 1 or 2 then drops off steeply for 0. Just because the course B is better than A which is a 6, but worse than C which is 8, does not mean automatically that the course B is 7. There are a lot courses in 5's and 6's and even if course B is better than A, that still probably means it belongs in 6 more than 7.
Also, Doak 5 is a very, very good rating. I would be happy to play any Doak 5 course on any given weekend. There is no shame in saying a course in a Doak 5 or 6. That is a pretty good endorsement in my book.