They did change Ignis acting direction in the English version over time to some extend, yes. Ignis finally addressing Noctis as "Noct" for example already helps a lot. But he still feels different to Japanese Ignis. I know, there are some things that you can't exactly translate from so different languages and cultures. It's not just the words but also the tone and rythm...but I think they took too much liberties with Ignis. Why did they think it was a good idea to let English Ignis act much more distant to Noctis anyway? In the anime Japanese Ignis acts and speaks to Noctis as if he was his mom. XD
Gladio is also a character that has a pretty different feeling in English to Japanese. Japanese Gladio sounds much more lighthearted and jolly than English Gladio. There he sounds more monotone thus more serious, also overall gruffer. In Japanese he sounds like your best friend who likes to boss you around, in English he sometimes sounds straight up like a coach or a military trainer.
I think they did a good job with Prompto though...to say something positive.

They translated his slightly annoying but endearing Japanese persona well into how an American person of that sort would act.