Aimar is technically superior to Ortega. Also, I think he is more complete in his overall abilities. Ortega, at this point may have greater depth, but that is due to his longer experience in the game. All things considered, I think that he'll be successful when he finally moves to a big club in Europe and in the long term he'll be be a great player for Argentina.
Ortega's problem is that he probably underestimates Europeans. you know the usual South America attitude......All Europeans are square footed i am better because i am from South America BLAH BLAH BLAH!!!!!
Frankly Ortega dribbles in circles......You can't do that in Europe because its a more lateral game and the only real agressor from midfield is the playmaker and if the playmakers also plays lateral you go know where.
Lateral football is Prtega's style and it just cannot work.
Ortega has failed at Sampdoria Parma and Valencia.....I think it is Ortega and not European football.