19. Automail
Prosthetics were nice. Plain wooden things carved out diligently to appear as real limbs. There was no pain involved in their application, they were relatively light in weight, and they allowed those missing a leg or two the ability to walk instead of being confined to a wheelchair.
However, there were drawbacks as well. Namely that they severely decreased your mobility as compared to your natural limbs; a gap filled amazingly by automail. There was no way Ed would have been able to hug Roy as tightly as he had when they were finally reunited if he'd kept Hohenheim's prosthetics.