Norm, do you usually ride sand? I am curious if you have noticed a handling difference. A head stay would tighten up the chassis vs not having one. There is definitely a preference and is different from rider to rider. Some like a looser chassis setups.
Speaking more to that, KTM still builds their mx bikes with a chromoly chassis, while Japanese use aluminum. The chromoly chassis will flex more, which they state is an advantage, and they have a lot of supercross and mx championships over the last few years to back that up.
-Jason