I found it very hard to distinguish parts of the dialogue in places where I'm sure it affected my ability (... such as it is) to understand the plot. Priya's role in the story, in particular, depends mostly on supposition on my part. (This is not a criticism of the actress, who strikes me as compelling.) The dialogue is muffled, but Tenet overall is loud -- oppressively so. It's like the sound designer decided to pummel the audience into submission as a way to induce anxiety, if not to invoke a more nuanced emotional response. Nolan's work relies, I would say, extraordinarily heavily on sound design. The storylines of his movies often seem, I daresay, more profound than they are, because of the physical (and thus emotional) resonances being flung at us.
The movie is fascinating as a feat of narrative construction; it doesn't really make any sense, but it's maximum Nolan. It's the most I've ever liked either Pattison or Debicki (how tall is she? That lady's about 80% torso!) John David Washington works as the calm, trying-to-be-rational centre of the causality maelstrom; he has a genuine gravitas as well as a certain Bond-like opacity. The film is visually gorgeous, and all three leads (speaking of gorgeous) can wear the hell out of a beautifully cut suit. Branagh is in his accustomed villain mode, which is to say he's way, way over-the-top; a drenching, sky-high geyser of malevolence (not ineffective; just not subtle).
(OT: Just out of curiosity, what about the criticism of Bane's voice struck you as off the mark? I could never figure out why he needed to sound so much like Charles Laughton, but that's more a question of performance than of aural design.)