No, they don't take more time to render than before, displacement is even faster, and cleaner. The strata filter is indeed in the function editor, it's a filter like any filter you basically place between the fractal input and the altitude output. But there are other ways to use it of course.
Chipp, those godrays are wonderful, and you didn't say that you don't even need clouds anymore to get them, like your 3rd example shows, you can get crisp godrays through tree branches.