>>279835790The difference between the speaking styles of the two parasytes is a really brilliant touch, I think.
Both parasytes are equally cold and emotionless, but the circumstances are different between the two of them.
Shinichi's relationship with Migi has been contentious and Shinichi has been put through hardship partially because of having Migi.
Uda's parasyte, despite still not actually feeling love, did save his life and hasn't really done anything to make his life worse. Which gives off the impression that he's a nicer parasyte.
The fact that Migi speaks in a formal, emotionless way while Uda's parasyte speaks more casually reinforces this impression, even if it's purely due to coincidence that Shinichi was a student and Uda was a guy who watches a lot of TV.