Some Decks hang on loose chains, so when the deck trys to scalp on a bump, the deck rolls on the Anti Scalp wheels on the deck, stopping the mower from scalping. This deck is more firmly held in place by hardware, that can move a little, but it doesn't really float like the chain mounted ones.
And yes, we have a sprinkler system. This is Texas, and it's pretty necessary if you want a green lawn. Really, finally got the lawn about perfect, it might not stay that way!!