Tough question. I would think that if you have to neck the pipe from a DC down to fit a pickup at the saw that any advantage it might have had would be eliminated. Especially if the shop vacs have way higher inches of water or mercury lift ratings.
The router fence pickup is similar but there are other factors too. If you don't have a stationary table up against a wall then the pipe from a DC could be a nuisance and the shop vac would be much handier. I enclosed the area around the bit on my fence and attached a small to mid size shop vac and it gets around 95% of all the dust so you don't have to have a powerful unit to get the job done.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.