This is much better than what we got. It has a much stronger political subtext, i.e. that of codified law vs. natural law. Because the Jedi really were taking over, they were extrajudiciously executing a sitting head of government/state. As an officer of the Republic -- at least, I think he was an officer, probably General Kenobi's aide-de-camp -- anyway, as an officer of the Republic, he was duty-bound to protect the person and office of the chancellor against the coup attempt.
On the other hand, Palpatine was evil.
On the third hand, so were the Jedi in Anakin's humble opinion.
That's the stuff of political drama; Anakin is torn between two means to a just end, two paths to preserve the Republic, and he chooses one. He supports Palpatine as the strong executive, leading to his buy-in of the Imperial ethos. In the version we got, the choice is different: go kill a bunch of Jedi and I'll give you a dubious chance of saving your wife, otherwise she's going to die according to some dream you've had. This doesn't lead into him becoming an Imperial; it makes him kind of a wuss. Now, that's certainly a valid interpretation of Vader: I was onboard with Veitch's "weak man in an iron mask" years before the prequels. But lots of other people aren't.
The only problem is with the dialogue itself. "Hurr, I can't believe that the Jedi was rilly gonna take over!" I'd have written something like, "All along ... They've been plotting all along. I should've sensed it. I'm sorry, sir, I failed you." That adds a little paranoia, and emphasizes his subordination to Palpatine.
EDIT
I just checked DE; Palpatine called Vader, "a sick man in an iron mask," and that sickness was the fact that, "his heart was possessed by the impotent side of the Force." So it's not really a weak Vader, but it's still a line that inspired a certain amount of rage in fandom.