[Water Warrior 2]

If I remember correctly the British auto industry would list piston travel in there advertising and owners manual. Never thought much of it at the time but it makes sense from a reliability standpoint. Yeah, we are going back a few decades. Modern engines in cars don't seem to worry about piston travel. Better materials and oils make things last longer. Oops, should include much better research and design too.
What was once considered an exotic design such as roller cams, overhead cams and roller rocker arms were for the rich and famous willing to spend the $. These designs are very common place now for their longevity and reliability.
The GZ may suffer from an older design but it is also the reason it is a popular machine. It is much simpler and fits well with it's target market.