Well, I sure notice a difference.

I work in final Cut pro, and if I want WMV files, I'll actually print my movie to tape and then capture it with windows media encoder so I can get the cleanest print of my movie.

If you use Sorensen, you capture into an AVI file, so you're now using a second codec to encode a file that's already been encoded.

You'll also have more problems if you're using WMV files encoded from AVI files using Sorensen if you're streaming Multiple bitrate files. Our customers all complained about movies freezing up and stopping until I started just capturing directly into WME.