For every voice sample that Unreal offers on the front page comparison, I found that the Unreal voice mashed up words (or tried to speak syllables too quickly), most noticeably on "synthesis." I did notice some more natural-like pauses and cadence, but the clarity of speech wasn't as good as the AWS example. For anything I could think that I would want AI-narrated content, I would prefer clarity over natural sounding nuances.