If you have time it's almost always better to sell private party. Yeah, it can be a hassle, but if you set it up
with your lending bank/credit union ahead of time, they can have all the paper work drawn up and it's really seamless.
I did a private party sale and a private party purchase recently that way and it was slick.
Now I have a private line to a lending agent at Mountain America Credit Union, I'm not sure if that's a perk, or a sign that Dave Ramsey would disapprove of my car buying habits...