Heaps of posts about this, do a search.
In brief what happens to the video before it gets into the computer can have the biggest impact on the final outcome. Once the analogue video is converted to digital many of the problems can be hard to impossible to fix.
I downloaded Neat video and the test file and the sample avi file (mpeg 4) will not load onto the Vegas 7 timeline. It does seem a bit complicated, much like the Deshaker plugin in Vitrtual Dub. I am assuming that's all I need are a few good templates. (like the Marines)
Or maybe a johnmeyer script.
I had been using Neat Image for stills with amazing results and had somehow forgotten about Neat Video. This afternoon I went ahead and spent the $99 for the Pro version for Vegas and applied it to a particularly noisy video I had that was recorded to 3/4" in 1976. I had tried everything over the years to reduce the noise in this video and had never gotten it to look completely acceptable. Well, what Neat Video did to this clip was absolutely astonishing. The noise is gone!
I then tried it on some HDV that I had shot with my V1u. The clip had a fair amount of noise in it because I had to crank the gain way up in a low-light situation just to get the shot. I had been contemplating just not using it because of the noise, but after applying the Neat Video plugin, the shot is now perfectly usable. The HD detail is still there, but the noise has vanished. I'm impressed!
One slight downside to it is that it's very CPU intensive although it is multi-processor enabled. Even on my overclocked Quad-core, a 20-minute DV clip took about 1.5 hours to render. A four-minute HDV clip took about 3 hours to render. Nevertheless, for these kind of results, I'm not going to complain about the render time. This may go down as one of the best $99 purchases I've ever made.
Neat Video is much like Sony's audio noise reduction in that getting good results is an art. It's going to take some experience to select just the right noisy area and to apply the correct amount of noise reduction. The interface and controls for Neat Video are exactly like the Neat Image software, so I was able to pretty much jump right in. However, it took a little while before I got proficient in Neat Image to begin with. The process in both programs is fairly well automated so you can get decent results right away, but the controls are there to tweak it further once you learn how the program is "doing its thing." Great fun! I wish it were faster, but only because I want to have that "wow, that's amazing" moment sooner than later.
On interlaced material, I use interlaced. Neat Video will analyze and process each field.
Even though Vegas operates in RGB, I have noticed slightly better results using the default "YCrCb 601." It makes sense to me that the noise reduction would be more effective for Neat Video to deal with the luminance and chrominance separately. For HDV material, I would think that there should be a "YCrCb 709" setting. I'm going to get in touch with Neat Video about this. They also have a user forum and I'm going through some old posts now. I plan to become a semi-active forum member there for a while.