I was confused by this and the sibling comment, but apparently "top-loader" in the US sense means a type where the drum's spin axis is vertical – which I didn't

I was confused by this and the sibling comment, but apparently "top-loader" in the US sense means a type where the drum's spin axis is vertical – which I didn't even know existed before this thread. "Top-loader" around here (Northern Europe at least) means a design where the spin axis is horizontal but you load and unload the machine from the top, via a hatch on the side of the drum. Because the drum is oriented the same way as in a front-loader, water usage should be equal.