All I can say is that your explanation (essentially saying Vader had no reason to flip out once he settled into his role as a powerful Sith) doesn’t really help make Anakin and Vader seem like the same person to me. I mean ultimately this is subjective, but I just can’t really picture Darth Vader saying a lot of the stuff Anakin says with the cadence or wording that Anakin uses. As one example, I can’t imagine Vader saying “Liar!! You’re with him! You brought him here to kill me!” Instead, Vader would just say “You have betrayed me. You have brought Obi Wan to kill me.”, while pointing his finger in Padme’s face.
Exactly, and this is my issue. I watched the saga 1-6 in chronological order. And connecting the two required so much suspension of disbelief I gave up. It’s such a radical change in characterization that there needed to be on-screen development showing him going from that emotional mess to the cold collected mask from the OT. But there isn’t. Either that, or just have OT Vader be the dark half of his personality from the get-go.