I have been using Neat for many years. There is a trade-off of grain removal vs image blurriness. Sometimes you can play with the temporal and spatial settings and find something which works. Generally I let the image clarity win and allow some grain. I have found that Topaz Video Enhancer AI does an incredible job of removing the grain while not blurring the image. It is an expensive option. Topaz has a free trial. It is not a plugin for Vegas. I run the newly captured video (I capture mostly 8mm, S8mm and 16mm) through the Topaz software and take that output (an MP4 file) as the input to Vegas. The software is a resource hog – likes a good video card and lots of memory, but works great. Grain is the big issue with 8 & S8 film. Dirt isn’t “noise” and isn’t removed by either product.