What is the difference, if any, between using apud with the name of a town, and using the locative form of that name?
Reading Suetonius Tiberius 40, I noticed this usage:
statimque reuocante assidua obtestatione populo propter cladem, qua apud Fidenas supra uiginti hominum milia gladiatorio munere amphitheatri ruina perierant, transiit in continentem
My first thought was that this might mean "near Fidenae", but presumably the amphitheater would be in the town; and Alexander Thomson translates: "But immediately, the people of Rome being extremely clamorous for his return, on account of a disaster at Fidenae, where upwards of twenty thousand persons had been killed by the fall of the amphitheatre, during a public spectacle of gladiators, he crossed over again to the continent". So is there no difference between this and the locative Fidenis (which is found in Cicero and elsewhere)?
As another data point, Tacitus, recounting the same event, also uses apud (though with a singular form of the place name): "nam coepto apud Fidenam amphitheatro Atilius quidam libertini generis..."
Lewis and Short (section II B of the entry) give a definition of apud as "At, in = in with abl. or gen. or abl. of place", which seems to imply it can also be equivalent to a locative.
So is apud with a place name completely equivalent to a locative, or is there any difference at all, whether in meaning, style, or author/period-specific preferences?