Yes, I have a pair I've used on both my KX450 and KX125. They are the alloy-bodied, gas-charged units, with the threaded preload adjustment. In short, I've found them to work well. They are quite expensive (high $600 if I recall correctly) but they are a quality unit. The spring rate I received was perfect. Their other advantage is that despite being alloy-bodied, gas-charged etc, they still look right on a pre '75 bike, mounted in the conventional 'right way up' position.
Regards
Ken