The trick to good video capture on PCI Powermacs is writing to a drive that is fast. For years I couldn't figure out why the video I captured was always full of dropped frames and choppy. I then figured out it was due to the slow write speed on the internal SCSI drive. I added in a PCI FireWire card and used an external FW drive to write the raw footage, and it looks great! So i've captured straight from VCR onto my 7600 and loaded it up on YouTube and it works pretty well. I've never used anything other than the built in video ports though.