We used to tow our van with the D1 (and my Volvo 740, and now with the D3). It's perfectly balanced. Fully loaded it's about 1600kg, and I can get the ball weight anywhere from "floating" to about 150kg depending on how I load it. With the Volvo it needed a bit more nose weight to keep it steady, with the D3 I just need enough on the nose to stop it "clunking".
I really miss the D1, but the wife hated driving it.

