Bruce, I'd be interested to see if you did a rotisserie experiment and comparison (qualitative of course) with the grate method. I'm trying to dream up new rotisserie ideas besides chicken, which is delicious. Tomorrow I have a ton of yard work to do, so it will be a perfect day to let the natural gas flow and a nice piece of meat spin.
I'm also trained in thermodynamics, but tend to agree with Larry when it comes to grilling, experience is a major factor.