If you are converting from very high definition videos like DVR-MS HD or WMV HD then you will lose some quality. Going from a high definition to any video format is considered a downgrade. MPEG 1 is considered a downgrade. Even MPEG 2 is considered downgrade when the source file is a HD. MPEG 2 is still considered the highest resolution standard format for DVD playback. Other formats such as compressed AVIs are also downgrades. The quality of AVI depends mostly on the compressor used. DivX encoded AVIs generally have the highest compression for large videos. However, you have to expect some loss in quality. The trial version is only limited by a brand it adds to all converted videos. The trial version does not affect the video quality.