I think many of Pereyra's strengths show better in a better team. What I mean is that his technical ability and decision-making is on the same level as the better players so you can see him make interesting combinations and movements in attack. While at Udinese perhaps he couldn't show that part of his game because they were always trying to defend and counter or he only had one decent player to combine with in attack, that being Di Natale.
You would have to be watching Udinese's practices to get a really good sense of the player because you were never going to see Pereyra play in an environment where he has this much possession and attacking responsibility in an Udinese match.
I mean, in the context of the national team, at least now you can say to yourself that it's possible to see him combining with Messi, Aguero and Di Maria because he can actually play fast, one-touch, attacking football.