I am using full version of J River and absolutely love it. Totally woth the price. I was very hesitant to buy it until I tried it. There is a great set up guide on Computer Audiophile
http://www.computeraudiophile.com/content/Windows-7-Audio-J-River-Media-Center-14-Configuration says setup for windows 7 but options are almost identical on Vista. Give the demo a try I don't think you will regret it. If you would like some help setting it up send me a PM or post in this thread.
Not only is it great for audio/video quality but it has some really great library features such as cover art lookup. I also love the way it has unobtrusive links to Wikipedia, IMDB, Amazon, and such. If you are listening to a song you can click Wikipedia and it will bring up the wiki right in J. River. Some really neat features.
It also gives you options of what video decoder you would like to use and lots of great features. I have really fallen in love with it. A great, great program!
Video playback looks great and it is really fast for having SO many options!!! I know I said great features 1000 times in a row, but it truly does have tons and tons of great features!