Regarding the dialogue: on my second watch (with subtitles) in the (few) scenes I wasn’t able to hear the dialogue clearly I realized it wasn’t relevant/important to the story. I believe these scenes were only about atmosphere, that was the moment I did not mind anymore and just enjoyed the bombastic sound scape.
Seriously, I loved Tenet! I had to watch it multiple times to finally understand how they moved through time relatively to the opposite side, what happened how, and it was fun and really well thought out. I loved this take on time travel!
Yes, you can understand the movie after watching it once. But there are so many little details that you won’t get if you don’t watch it multiple times, I had fun puzzling it together!
It’s in my top three of the Nolan movies! And the music was great, I did not mind that it was too loud!