They call the deck material Nexite and it has a lifetime warranty and makes for an incredibly light and easy to push/maneuver unit. A friend has two of them, the first on my recommendation, the second based off of his fondness for the first unit. He wouldn't have had to buy a second unit, if he'd of kept up on the oil changes and keeping fresh fuel around, but I digress. The first unit made it roughly 5 years with probably 3 oil changes, 0 winterizations and general neglect. It was the HRX217 IIRC and between the mulch, bag and rear discharge functionalities was a hell of a mower. His newer one is hydraulically self-propelled and has a blade brake clutch/blade stop feature, which is nice, partially due to the lack of re-starts/heat cycles when bagging, but nicer due to having an actual throttle. The old one ran at a governed throttle setting, which was fairly high but was still fairly miserly on fuel. I would buy either mower, hands down except for my wife only wants to discharge and doesn't like the rear discharge. I need to see if they make a installable chute to deflect clippings from the rear to the side.
The wheels are also ball bearing units that are wide which makes the mower easy to push and allows it to track very easily. I'm sold on them.
Also FWIW, he mows a smaller yard in town. I mow around 7.5 acres in the country (mostly w/my Hustler Super Z) but do a lot of pus mowing around certain areas. whether "finish" mowing, or nearly bush-hogging, his mowers did better than the Snapper that I used growing up and many Toros, outside of the top-end commercials. For the money, they're probably the best thing going. His old version is still sold and is around $500 which is far and away more mower than you get at Lowes for that price or a few hundred more.