Another thing to note about the difference in fighting is that it's well documented that the costume on Vader was constrictive, and even required a separate helmet for the guy who would play Vader while he was dueling. So not only do you have guys who don't really know what to do but your guy who is going to do much of the fighting is doing it clumsily at that. If anything I take away from the OT is that taken as a whole of this franchise, its a trial by fire when it comes to what it accomplished. Technically it's a night and day difference as CGI, proper stunt fighters, and better costumes result in a more streamlined experience, but takes away the heaviness of the duels. Pretty much due to them no longer being literally weighed down by costumes. CGI can make a giant monster, but it can make a Muppet doing flips look silly even when its composited correctly.
This thread kind of makes me want to go back into the sequel trilogy lightsaber duels to see how this sort of thing advanced.