And what are those reasons? Because they're not ideal or palm smears? BTW, that's the question at hand by the OP? Most people don't like waterfall keys because the weighting is different, the action is stiff or loose, is not ideal for playing piano. I've never read or heard waterfall keys were less ideal than standard keys for playing organ and doing palm smears, never. You're speculating about various clones and stiffness of the keybed. That wasnt the question proposed and even if you do think that waterfall keys arent ideal for organ palm smears then you're the first person I've ever heard that from, so from a standard deviation point of view, you would be an outlier. So for the question at hand I don't see how I opened up a can of worms. Perhaps for other reasons, yes, but for organ palm smears, waterfall keys are preferred. And like Anotherscott, I adjust my technique of palming across the top of the keys on non-waterfall keys, but have bloodied the hands when in the heat of battle on stage I come up short and the non waterfall edges catch my hands. This never happens with waterfall.