Value Judgement -
The use of statistics - X = better, Y = worse
X has used more statistics whereas y has used minimal to no statistics in their argument, giving x more backing for his claim making it more understandable and trustable to the witnesses of the argument.
Presence of vested interest - X = has one, Y = Doesnt have one
Use of opinions - X has many opinions, Y has minimal opinions
Language - X has emotive language, Y has direct language