In theory, the higher ratio is more stable at higher rpm. Adding ratio will increase you "@.050" lift numbers, because you get to .050" of lift sooner. So you gain a few degrees of 'useful' duration as well as total lift. It's more stable because you're moving the valve further without moving the heavy parts further. Heavy parts have more inertia. A .600" lift cam with 1.5 ratio rockets will valve float sooner than .600" lift cam with 1.6 ratio rockers with the same valve spring pressures. Am I making sense here?

That said, the rest of the combo has to be able to take the extra lift. As said, valve to piston clearances, coil bind, and locks/retainers to guide clearances need to be able to take the added lift when you take one combo and just toss the higher ratio rocker at it.

There's also the debate on side loading the valve stems, and swept area of the valve stem. The higher ratio will sweep further to the edges of the stem, and can add extra side loading

The EFI magnum engines all left the factory with 1.6 ratio rockers.