Just a different approach to the same problems. Pauls design needs the Apron rigidity and stabilisation because there are only crossrails none lenghtwise like on my benches that pretty much serve the same purpose, both designs are rock solid and i’m sure if properly made dont move.
At the end of the day everyone has to pick their poison, just comes down to the kinda of work you wanna do and what your personal perference is.
I mean its not like you cant remove or add an Apron depending on if you like it or dont. If you add lenghtwise rails to Pauls design there should be no stability issue whatsoever if you decide to remove the apron down the road if thats what you wanna do.