I fully agree that medieval armor was meant to be impressive — but so was ancient Greek and Roman armor. Everyone likes shiny metal and tall plumed helmets.

Lastly, the Romans did not have a great track record against cavalry, and they obviously had never had to deal with the shock of a lance charge from late-medieval heavy cavalry with stirrups. They had all kinds of strategic advantages — large numbers of professional troops, experienced generals and centurions, siege engineers, etc. — but their heavy infantry might find itself mauled by a first encounter with mounted knights.

Not that the armor of the ancient Greeks was without criticism, but it seems to me that at least when it comes to the lamellar breastplates, they had the medieval folks beat.

I am still of the opinion that the armaments of the Roman legions, with large interlocking shield walls, lamellar breastplates, metal shoulder and arm protection, helmet that protected the face and neck to a certain extent, javelins that could be thrown but not thrown back, and short swords made for thrusting up front, and long spears in the ranks behind, was pretty darned good for an infantry unit. The guys with the big, long medieval swords might have had an advantage in single combat, but the Romans didn’t typically fight in single combat. I would argue that a bunch of medieval knights fighting in their typical manner (in force but not necessarily as a unit) wouldn’t stand a chance against a Roman centurion and his men, even mounted.