I use m2t files and use the HDV 1440 x 1080 29.97, then select progressive scan if the final video will be watched on a non crt TV. Do you ever see what looks like a comb edge on fast moving video? The progressive setting will fix that. Also if you plan on rendering the files more than once or do any chromakey work, I would render each m2t file to Cineform avi. This format is much more efficient than m2t and can handle several renders. If your computer is fast and your not rendering more than to the final format, m2t files can work fine with the newer versions of Vegas like 7 or 8. Danny