I've had Honda mowers with both decks (aluminum & plastic), the plastic is lighter than the aluminum or steel decks and cleans-up easier. If your property is very rough or full of rocks I recommend aluminum or steel. When you turn or pivot the plastic mower it is essential to depress the handle, to raise the front wheels slightly to avoid stressing the wheel mounts. If you don't do this the deck will eventually break at the wheel mounts.
