Star Wars Episode III is indeed much better than I or II; and that is what makes it much worse.
In explaining my paradoxical judgment, I forebear to nit pick. I will not ask why Jedi can apparently use their light sabers to deflect an infinite number of blaster bolts coming at them from every conceivable direction until order 66 is given, whereupon it suddenly becomes relatively easy for clone warriors to pick them off. I will not ask how, if Padme dies right after childbirth, Leia can remember her mother as "beautiful and sad." (The conversation when Luke asks her about her memories in its own context always seemed to me to be about her real mother, not her adoptive one, because Luke is trying to establish some connection with his own, whom he now knows to be the same person). I will not ask why, since the first Death Star is already well under way by the end of Episode III, and an entire galaxy of slave labor is available, it is only just being finished twenty years later at the time of Episode IV. All this I omit, being studious of brevity and disposed to charity.
O.K., then, on to the good part. I agree with Ken Morefield (http://movies.kenmorefield.com/) that the first two movies did an inadequate job of building up Anakin's nobility so that his fall could be from a sufficient height. But I thought the first half of Episode III significantly ameliorated that problem. We see a more mature Anakin with a better relationship to Obi Wan, who insists on saving Obi Wan during the rescue of Palpatine, and who is feeling a real loyalty to the Jedi order for the first time just as that loyalty is coming into conflict with the lies he has been fed by Palpatine. I think we do see the Jedi he could have become, just in time for that destiny to be sacrificed on the altar of his misguided but natural and understandable "attachment" to Padme. This irony heightens the sense of tragedy, as does the horrible irony that the death he turns aside from the path to prevent is caused by that very turning aside from the path to prevent it. That is an irony worthy of Oedipus. At that moment the film rises to the archetypal and made me want to forget all the inconsistencies and plot-holes and grant that it had achieved in spite of them a grandeur rivaling that of the original trilogy.
But . . . it all came crashing down into the incoherent mess Morefield describes because of one horrible, intolerable, and inexcusable line. When Obi Wan confronts the newly fallen Anakin, he is convinced that the fall is real when he hears Anakin declaring that if Obi Wan is not with him, he is his enemy. Obi Wan's response is, "Only a Sith deals in absolutes." Well, I guess we see where that places historic Christianity, or any other traditional view that takes certain verities as unchangeable and non-negotiable!
But let those of us who are believers bracket our personal disappointment and offense as Christians, and think of the line only as it functions in the context of Lucas's myth. I wearily ask if you do not smell something fishy, not about the content of Obi Wan's statement (which is bad enough), but its form. It is an absolute statement! Only a Sith deals in absolutes. Therefore, if Obi Wan's statement is true, then he, having just dealt in an absolute, is a Sith Lord too. And if that is the case--and logically it follows inexorably--then what is the fight about? What is the difference between the light and dark sides of the force?
A moment in the original series foreshadows this fall into relativism. Luke thinks he has been deceived about his father, whom Obi Wan had claimed to be dead-"from a certain point of view." Luke finds this rationalization incredible. "You're going to have to realize," Obi Wan responds, "that a lot of the truths we hold depend greatly upon our point of view." Oh, really? Then how do we respond to Anakin saying, "From my point of view, you're evil"? What basis is left for distinguishing between the Light and Dark Sides of the Force? For claiming that the choice between them is anything more than an arbitrary personal preference? If only the Sith deal in absolutes, the whole Star Wars ethos collapses into nonsense so nonsensical that Coleridge's "willing suspension of disbelief that constitutes poetic faith" becomes simply impossible, at least for me. And the worst part is that it taints the whole mythos, three episodes of which I loved.
So then, you see why I say that "Star Wars Episode III is indeed much better than I or II; and that is what makes it much worse." Because it does at times rise to the mythic power of the original trilogy, the message that "Only a Sith deals in absolutes," that, in other words, anyone who believes in absolute truth is evil, will be disseminated far and wide, and disseminated effectively to an audience with whom it will powerfully resonate. Logic has little power with a generation that has been taught to "trust its feelings." But my message to them is this paraphrase of one of Obi Wan's better moments: "Be mindful of your thoughts, Master Lucas; they betray you."