There are issues about the general quality and usefulness of Genuine Fractals vs. other resize methods [lanczos, b-spline, etc.]. There are many sites that discuss, and post examples and comparisons.
Bottom line, there’s no such thing as “resolution for free.”
On this subject, check out FredMiranda.com. He has a slew of handy actions and such … but check out his stair interpolation plugin, and comparison to GF: