I drove from Cortland last June/July, taking 81 to 64 in Staunton, VA, and linking up with 95 outside Richmond. Route 64 goes through the mountains, which starts out pretty but gets tedious and I think added time to the trip. Coming back I stayed on 95 to Route 17 in Fredericksburg, which seemed to go faster, even though it went through a few towns and I encountered lower speed limits and a few traffic lights. VERY pretty horse country!
We took three days coming down as it was our first time driving and I was the only driver with two children, and then swung to the opposite extreme and came up in one shot - almost exactly 18 hours - so I don't have a specific halfway recommendation for you. However, I'm planning to drive again this summer and am looking at anywhere from Fayetteville, NC to Savannah, GA depending on how I feel once I get there. I definitely want to be more than halfway when I stop, so that next day won't feel so taxing.
We stayed at a Holiday Inn in Gettysburg our first night and a Motel 6 in Savannah the second, a big mistake as we were sort of appalled at the difference in quality (yes, I expected it, but it was hard to accept nevertheless). I have already decided that I'll spend the extra cash to have a nicer hotel no matter where we stay. At the top of the Transportation Forum here there is a link to exits on 95 that helped me tremendously in deciding where to stop for food, gas, and lodging options.