So we're on the third iteration of firmware for AirPods Pro now, right?
I use mine mostly in a noisy environment, and, not having used noise cancelling headphones before, it was bliss. Worked amazing well. And then, noise cancelling started working quite obviously less well. I assumed they perhaps weren't sealing as well as when new - maybe the rubber tips were now more slippery.
I doubt that's it, though, because now that I'm on the current firmware, I hear the same things others here have heard - they're warmer now, but those airy highs I was enjoying are lessened. And noise cancelling is still nowhere near as good as at first. What a bummer! (I assume when I noticed worse NC it was firmware #2)
My preference would be to go back to the original trade-off - great noise cancelling but slightly sterile but very precise sound. Even though most will just play their music loud enough that the current level of NC is ok for them, and they're gonna be listening to vocals so the midrange boost is good for them, that isn't me, unfortunately. I was really digging all that detail before, and the ability to play it not as loud.