Primland is really, really cool, but really, really expensive, and a little bit hard to get to. If none of that matters, it's worth seeing.
In the same general area is the River Course in Blacksburg, which is far less expensive and certainly worth seeing.
I haven't seen Holston Hills, but from everything I've heard and read over the years, that seems like a clear Option 1 if you can work it out.
The thing that you didn't mention is what you have or have not played in the Pinehurst area already, and/or what you are playng this time. It is VERY hard for me to tell anybody to play anything else other that 1-5 at Pinehurst if they're going to be there and haven't seen them before; the place is a cathedral of golf. And going beyond that, I'm such a fan of Tobacco Road, that I'd have a hard time not telling you to see it if you haven't already.
One other note: If you haven't already, be sure to play The Cradle at Pinehurst. You'll never have more fun playing golf than doing that with buddies and beer after a day at Pinehurst; it's just silly, crazy fun.