I use Vuescan software with my V800 and Nikon Coolscan IV. It does support a lot of scanners and ones that I have used over the years. Silverfast's main disadvantage as far as I am concerned is the limit of one scanner per license.
Unlike some of the previous replies, I am trying to get good scans straight off the scanner without having to use Photoshop or other image editing software. The setting that helps in this is setting brightness in the color tab to .7. This applies a gamma correction to the image. Do a preview with all defaults and then apply brightness .7 and see the difference.