I guess that P-CAV is better. It should be as yamaha patented it (i'm not an expert english reader, but that's what i think i've read from yamaha's website :P). Maybe that's why there are only a few P-CAV writers. As John said, P-CAV is faster and has to do few links (or speed changes if you prefer). I've tried both, and is amazing how a yamaha 20x is near as fast as my sony 24x. If you like reading so many unclearly tech papers, visit yamaha's web...