I recently went through the same process and had the same concerns. My transaction was a little bit less stressful as I bought a car from a site member recommended by another member. Even so, I had never met either party and at the time I wasn't a member of the site so I was still running on blind faith. So I decided to suffer the expense and traveled cross country to meet the seller, see the car, deliver rather than mail the check and bring the title home with me. Then I had to arrange cross country transport which required patience waiting for the car to get picked up. Once picked up it arrived quickly and was in perfect condition.
In the end everything went very smoothly with both the sale and the transport.