Thanks for the info Jim.
Looks like there are many ways to skin the cat. I have tried running my stocks on the ears over the years and have always had vertical that way. But perhaps my ear material was too stiff to create a lasting "ledge".
When the DR bag came out a few years ago, I tried it and fell in love. It allows the stock to track like it's on a rail and the vertical went away. Also, the first record shot goes where the sighters say it should which was something that only happened 50% of the time before. I also love the ear heighth and how stable it is. For a knob tweaker like me, I like stability.
Here's a group I shot just this past weekend off this bag. Once I went to the record, I ran the group as fast as I could and never touched the elevation or windage knob again. I didn't time it, but I'll bet all five shots were downrange in under 8 or 9 seconds. Now that's tracking!