Not really comparable in my opinion. Box Royals offer actual tactility, although what they do offer is often considered overly harsh. Zealios on the other hand give a more traditional tactile MX feel, which isn't really tactile; it more or less feels like a disrupted linear switch. Keep in mind this isn't necessarily a bad thing. Most people dislike this type of tactility, hence the reason Zealios V1 are being discontinued for the more tactile Zealios V2. But some (myself included) love it. It gives the user feedback that a key was pressed, but it doesn't dictate how you type. The Royals, on the other hand, are going to force you to bottom out. If you don't like that, then too bad because the Royals don't care. I would say Royals are for those that want extreme tactility and don't mind / aren't susceptible to a bit of finger fatigue after long periods of time, whereas Zealios are for those who want light, passive tactility.
It should also be mentioned Royal's tactility is all loaded at the top of the keystroke, whereas on the Zealios it's halfway down. Also, both switches are quite smooth stock, but Royals, being of the box design, don't surrender to lube that easily. Lubing Zealios, on the other hand, turns the smoothness up to 11.
But all that's in reference to feel. In terms of sound, relatively speaking both switches sound like ****. Especially Royals once they start to click. (Lubed Zealios sound OK)
