Celtiberian swords

[Gobae]

2.Apart from good iron and workmanship what set the celtiberian leaf-shaped short sword apart from say a standard xiphos? Width and different leaf-shapes yes? Better thrusting characteristics? Can't really understand why a roman would be impressed by the celtiberian sword unless it was purely a workmanship, metal quality issue they commented on not the blade-shape itself.

From what I've seen of assayed Celtic ironwork ("The Celtic Sword" by Radomir Pleiner, "Early Irish Ironwork" by BG Scott) it's all over the board with regard to ore, bloom, and heat treatment quality. You could end up with a smith who knew how to do proper heat treatment but was cursed with a bloom that had next to no carbon and therefore the process was for naught. Alternately, there are examples of smiths doing no heat treatment and just lucking out that the ore and resulting bloom were fantastic for blade work.