The latest release of Viewscan has transformed it for certain scanners. I use a Canon 9950 for 4x5. I have used Vuescan for years because of the control and because I can use the same software for all of my scanners at no extra costs and because upgrades are frequent and FREE. Lately I changed to Silverfast for multiple pass scanning because it has a method of dealing with creep between passes, and because it gives good control over the output. Then I tried the newest version of Vuescan and it has added multiple sampling for the 9950 and some other scanners that I did not think supported it. Suddenly you can do X samples in one pass, so there is no creep and no alignment problems! The scans are terrific, as good or better than the best of silverfast, plus you get Vuescan's extra scanner controls.