A saturation boost doesn't impact sharpness, at least to my eye. The advantage of scanning Astia is that you can really punch up the Unsharp Masking parameters. In particular, Threshold can go down to about 4, whereas it requires 11 with Kodak E100VS and about 6 with Provia 100F, or 14 with Provia 400F. The RMS Granularity of the film you scan is closely correlated to what you can set Threshold to. What you want to avoid is exaggerating the grain in the sky or large areas of the same color or tone. That is a limiting factor way before you get the unsightly halos between adjacent high and low key subject matter - halos which characterize oversharpened digital prints.

Amount can also be increased some when you use Astia. Radius doesn't change much and seems dictated by format size, ranging from 1.5 at the low end for 35mm scans to 2.1 for 4x5 scans.

To me, Astia 100F is the single best choice when you know you are going the digital hybrid approach. Minimizing grain is critical to keeping film images competitive for critical acceptance versus grainless digital images.

Gary Reese