Apparently, voicing a First Order Stormtrooper is very different than doing it for an original trilogy version of the character, because the First Order Troopers are much more emotional.
The First Order shares a lot in common with the previous Galactic Empire, including their reliance on white-clad Stormtroopers as soldiers.
Sam Witwer has done voice work for numerous Star Wars projects over the years, including giving voices to Stormtroopers in both of the recent Star Wars movies.
However, it turns out the First Order versions are very different than those that came before.