Originally Posted by adamqd
Post mustafar Vader is sustained by the Force and his armor, Physically he is as decrepit as a corpse anyway, as long as he had the force and his armor his age was irrelevant.
The real reason the fight in SW:IV was slow is because George and his choreographer's hadn't decided on doing acrobatic moves with stunt men yet, The in universe reason is probably because of Obi-Wans age and his dictation of pace using Soresu (IMO)
I totally agree. This was really the first time that they actually had a lightsaber act. Yeah I know that there was one in ANH, but that was lousy. They certainly did a much better job with the lightsaber fighting in ESB, but it isn't something that we are used to. The fights got better as the saga progressed.