When I was shopping for a mower I looked at the Gravely & Ariens line of Z turns. I did a side by side comparison of the two and when asked about any differences, the salesman admitted other than a higher HP engine and the paint scheme, they are exactly the same mower. Why spend more for a name (Gravely) if the lower HP Ariens suits your needs?
A neighbor of mine owns an Ariens and loves it.