I loved that Batman looks and sounds so calm, cool, and collected in this clip. Part of that is definitely Ben's expressions and mannerisms, but also the voice and its modulation. Batman's not screaming or shouting, he doesn't have to try hard to put on his "Batman voice". It's just coming out of him with ease, which was a little jarring at first, but it's almost a little creepy and keeps growing on me as I see/hear more -- especially after hearing it in the context of an actual scene.
I always liked the concept of Bale doing the growly voice, not only to mask his identity, but because it was like he became Batman whenever he used that voice. I have no problem with Bale's voice in the majority of TDKT, but there are times it was wonky and inconsistent. It also required too much effort from Bale.
Affleck's voice takes on that same concept, as he also takes this extra step to alter his voice. Since the Bat-voice is actually Affleck's voice, it's almost like his Bat-voice is a dark (and maybe demonic) mirror of Bruce's own voice, creating a further disconnect between Bruce Wayne and the Batman -- while also removing another shred or sign of his humanity when he becomes Batman. I bet criminals would be scared ****less of something like Batman chasing and calling out to them in an alley with this voice.
We've only heard Batman speak calmly so far, from what I can tell. I bet the voice will sound even crazier when he actually does get angry, loud, and/or intimidating. I wouldn't mind if they played around a bit with the modulation throughout the film. I could see there maybe being changes in volume, reverb, and echoes for the voice throughout the film in different situations.