I have about 15 Gb of MP3s in my collection about now. I have experimented with all methods of encoding and through long trial and error, I found that VBR is my format of choice. I don't mind the timestamp errors as I rarely use fast foward. My main concern was getting the highest sound quality and still have relativley average file sizes. That being said, I have used 100% VBR on the majority of my collection and I am very satified with the results. The typical file size is a little bigger than average (around 5-7 Mb) however the sound is indistinguishable from the source (in my ears anyway). I found that CBR files were too big for my taste. Hope this helps. I do agree with Tony above in that the Empeg player was my main reason for trying to get that perfect in-car sound quality. John