Slide film has a much higher dynamic range, which is also good for scanning-printing, because you can adjust the photo for print much better. That's why slide film used to be the reference material of pros in the old days. Exposure has to be precise, because the material can transfer precisely what you want and most light meters can do that. Negative film is less sensitive to exposure errors, which also means that it cannot transfer everything right. after scanning the colors come out perfect and saturated, because there is no conversion required. I use Provia 100 and that works great for my Nikon coolscan as well as for the reflecta MF5000. Adjustments one has to make depend on the paper you want to print on and not so much on the film. I will always prefer slide over negative. I have not much experience with high ISO films, but grain is mostly visible on the monitor and not so much on the print. I had scans (b&w), with strong moiree from the scanner, but there wasn't any visible on the print!