Had my old Z445 so many years with the mat that when I got the 915E it was the first thing I noticed was no mat. First thing I had to add. Only have 3.5 hours on it so far but what a difference between a Z900 and a Z400 series. Don't know why I waited so long.
I have two (2 ply) on my Z710A. When I bought my Ztrak I ask the salesman for one, and he sorta frown on any "give-aways", but, he realized the complete sale wasn't final. My neighbor bought a new Z930M and he got one, but, he didn't care for it and gave it to me. I think the two helps my old tired legs. The only thing I don't like about the mats is they sure collect a lot of dust, grass clippings, etc.
What did help my old tired arms was my invention on the handle bars that I can now rest my arms on the arm rests.