I just watched ANH a few nights ago. The Obiwan/Vader fight is really bad compared every other star wars saber battle. But, to give them some benefit of the doupt, they likely would have been rusty at that point. Neither would have likely been in a saber duel for over what 30 years or so.
I think it's a very good example of how the trilogies are totally different.
The fight is more than bad, it's terrible, and it was impossible to hide even with heavy editing. So I agree that on a technical perspective, that's by far the worst light saber duel of any starwars movie. But Alec Guiness is an excellent actor (a very long career, academy award, Golden globe for this role), served by great dialogues that build a character that is a sort of wise monk-like samurai telling ancient stories, he has a powerful presence on screen, so I care about him, I would not like him to die. So, when he meet his ancient enemy, there is some tension, you kind of worry, but this guy, and that's very consistent, he doesn't loose the fight because of his skill or a bad move, he embraces death with a very peaceful face and die without any blood. And he won by doing that. And that's just so cool, surprising and still consistant, that's deep and inspiring, that's the star wars I liked.
Darth Maul, I mean, great fight, so much better fight, but he can die, I just can't care, he doesn't have any characterization and dialogue. And the moment before he dies, and again the moment he dies, he makes a so stupid face... and that's not by accident, because the guy is not even an actor, he's a stuntman (and that's for real). You can watch it for yourself : https://www.youtube.com/watch?v=HPfgSFLrAVE
So, including the background, the ending, the novelty, the acting, I still prefer the scene from ANH. I don't really care about seeing a long chinese kung fu-like fight with bad acting and no character development, I can't be impressed or inspired by that.