In addition to quickly measuring DAC and DAH, the tabletop method has one other advantage: if you put up three or four guns together and view them from the butt end, you can quickly see differences in cast and twist of the stock that are more difficult to discern when viewing a single gun. If you look at the butts from the side, relative differences in pitch angle become more apparent also. I was amazed at the subtle differences in cast and twist in my Parkers, none of which had "obvious" cast.