I think Oakland Hills South definitely belongs in a kind of second-tier of great courses. I think it compares very favorably with all but a few American major championship courses.
It's actually better, I think, to talk about the classics that must be rated above it -- Shinnecock, Oakmont, and a select few others. And Oakland Hills lacks the charm of the other rarified classics that are not forced to adapt themselves to tour-level play - Cypress, NGLA, Seminole, etc. Because apart from the courses in that extraordinary group, I think Oakland Hills is outstanding and a first-class examination.
I do think that one of the best comparisons to Oakland Hills in terms of its issues is Riviera. Both built around the same time. Both courses hosted some of the best play on planet Earth in the 1950's. And now, both constrained by the dreaded distance issue. OHCC faces a crisis in that there is no more room for some of its very best holes to obtain the added distance they need. At OHCC, holes 1, 2, 10, 11, 12, 15 and 16 all need pushed-back tees if no one is willing to do anything about golf ball performance. Ditto for 1, 10 and about three or four other holes at Riviera.
Apart from the length issues at OHCC, they actually do have a nifty reachable par 4, and that is Hole 6.
Hole 7 at OHCC is a sore point that has been the subject of numerous committee- and consultant-driven makeovers, and none of them have been satisfactory. They need the ghost of Donald Ross to start from scratch on that hole. (Rees Jones could have done anything with his latest makeover and it would have been an improvement.)
Hole 16 is the Pamela Anderson of golf holes; famous, gorgeous, and mostly unnatural.
Hole 18 is a conundrum; a courageous architect would substantially re-work the hole, which is a par-5 for memebers, a beautiful hole, a lovely concept as a MacKenzie-style in-between distance/par, and, sadly, uncomfortable as a converted par 4 for tour players.
Anyway, there should be no surprise in that the majority of GCA members have it right about OHCC; those green complexes, most of which have never been touched by Trent Jones or Rees Jones, are pure Ross, and they rival Ross' acknowledged masterpiece, Pinehurst #2.