Step Turn,
Your comments are very timely. I've used "Gear down" in my downwind checks for many years, even though the majority of my flying is in fixed-gear aircraft.
I also have a float-rating and next month I'll be back in Canada and assuming there is not an early freeze-up, I'll be revalidating my rating in a Cessna amphib. It will be interesting to see how my brain copes with a new checklist item.