fyi, there's a possibility that Osage Grove will have its concrete tees installed this fall. The club is down to a couple of tee sponsorships to pick up, and then the plan is going to be to adjust all the big boxed gravel tees (currently with rubber tee pads) so that they are trapezoidal (like hole 12) and pour concrete.
In addition, there's been a huge amount of effort put in by Kurt, Gibby, and the chain gang out there over the past two or three years, clearing the edges of underbrush, adding alternate tee locations, wonderful bridges & stairs, significantly lengthening your options on 7, 14 & 15, etc. By spring, with new signage, it would be unfair to rate it any lower than a 4.0 course, and some folks will be rating it better than 4.5
Finally, fwiw, I REALLY enjoy our local courses in this order of (my personal) preference (to suggest to others):
Lincoln Ridge (best overall fun round based on variety and appeal to a broad range of players)
Idlewild (a MUST experience, despite its challenge)
Osage Grove (the up-and-comer)
Mt Airy (for the pro shop and all the extras, even though I call the long baskets the 'Ams be damned' positions)
Then I often suggest Cedar Sentinels out to the west, Monroe out to the north, and Williamsburg out to the east)
Keep on the lookout for Johnson Hills in about a year!