The English cast is mostly alright. I do think Prompto (especially), Regis, Ardyn and Noctis do a good job. Ignis (especially) and Gladio feel for me personally too different to their Japanese characters though. So, even if they deliver their lines well, I'm not really content with them. Gladio sounds too gruff and tough all the time, when he sounds actually more lighthearted and not nearly as monotone in Japanese and Ignis feels too snobbish to me. The kind of accent he has just brings all these stereotypical British snob characters to my mind. I'm glad he's addressing Noctis with "Noct" and not "Your Highness" anymore though.
Lunafreya and Cor feel a bit weak to me, just from the snippets that I've heard so far.
I will definitely be playing with the Japanese voices. I won't even try out the German voices because I know they will suck. Germany is usually very good at dubbing. Much better than Americans for example because we dub literally every foreign film or series for our market. Like in Japan, voice actors are in big demand here and they can make a good living from it. But video games, especially Japanese ones, do mostly get the crappy anime series treating. They are miles away from the quality that foreign movies or series are dubbed in. :/
Eww...the lighting of Luna's scenes is just bad. Even in less advanced games one console generation ago we had more cohesive and atmospheric lighting. It looks like she's on a theater stage with cardboard scenery behind her.