So, there's the obvious Sollux would have a lisp, Karkat would be tone deaf, all shouty and loud; same with Caliborn, Damara would speak broken Japanese, and Calliope would speak with a British accent. The rest would be dependent on their personalities, like Rezi talkin all silly and creepy, or Gamzee talking like the stereotypical stoner type.

I mean, we see characters write in other things rather then pesterlogs, like chalk, or letters, or books, so i don't think that typing quirks'll totally be lost.