After or rather during last weekends ride I changed back to WR timing. Having tried both I'd say it's likely that a well tuned WR is faster anywhere than a YZ. The YZ has more midrange power without doubt, but it lacks the spread and versatility of the WR. I'd say that the YZ may feel faster than a WR and give a rush with the midrange power but little more. For trail work you might as well be riding a two stroke, and it would be lighter. I know that you would rather I said what I really think but hey! it's a family site.