Pros- more stable than than tiller tree or a option if you do not have one, or space for one. easier to measure to the bench than set up a grid to eyeball from, and you can hang a known weight from the center while you make measurements.
Cons- ??, just remember that the physics are the same as longstring or floor tillering, in that the bend is not quite the same as it would be if truly braced. However, I use a modified rest/fixture on my tillertree that gives an accurate bend, and that fixture might work even better with this pillar setup. Thanks for reviving.