My initial thought when hearing N's dub voice was "safe." It wasn't really a voice that you would really remember and it wasn't really a voice that you could hate. It was just safe. It did lack the passion N should have had though.
Overall, the episode managed to fulfill a nice introduction for his character. I'm certainly anxious to see more of him. I also like how they decided to make the upcoming movie with Genesect canon to the anime, as this can be viewed as kind of prequel hinting at events to come.
I also did like the questions N pondered about. I'm sure those are questions we all have thought about from time to time. It was actually kind of deep for the writers to do. I was surprised they brought up such questions. It only made me like N that much more though.
I don't know what N said in the dub, but in Japanese he said something to Meowth like... "why would you speak human when Pokémon have their own beautiful language?" and that's kind of like... wow N way to be rude? Because that statement kind of puts down the amount of effort that obviously went into Meowth learning human. And N doesn't even know the reason behind it and doesn't care- he's not even asking "why" really, he's saying "you shouldn't".