I've done a fair amount of tracking with stereo vcr then dump to hard disk.I did A-B listening test first with the source CD and the differences were too fine for my 45 year old ears to detect (your mileage may vary).Yes,the rotary head spins on the bias so that it uses the entire tape width except for a strip at the top dedicated to analog audio.The video is interlaced with the stereo audio from its own separate head.I used the distance travelled by the rotary head over time to compute a tape speed equivalency factor of 1500 inches per second!
By the way,this is STEREO vcrs we are talking about.I think the old mono units just use the edge recording method mentioned above so you wouldn't get the fabulous signal to noise ratio of the stereo unit.
If you have a hard disk based recording system,this allows you to capture remote location tracks two at a time (stereo rhythm bed for demos?)and then bring them home to tweak.Multiple VCRs increase your capacity two tracks at a time.Try messing around with the vcr and I think you will be pleased.
Tom