Alan is right, if you are going that far on 77S, you may as well stay on a bit longer, fly past route 9 and hit 20 across. Granted you back track a little upwards to go to NMB, but it is 95% highway.
Now, I've gone many ways from Ohio. You can check out this post of mine about midway down the page:
http://funbeaches.com/forum/viewtopic.php?t=7749
I like the 77 - 74 @ Mt. Airy Route and as you can see by the post that I linked above that you can go toward Greensboro ( which I don't like) or go through Winston-Salem to Lexington and head down 64 to 73/74/220S.
The roads I listed aren't little county roads, where you could get lost easily. I found the drive to be easy. The traffic, to me around Winston-Salem was less intense than Greensboro.
Another issue is what time of the year are you driving down? We went in fall and found less traffic in certain portions of our trip. There are always race issues around Charlotte and other towns in NC/SC on weekends. Are you driving straight through?