Tough to compare them..In terms of ability, Amir>every fast bowler in the world today except Steyn
As far as Junaid is concerned, and this might have something to do with the fact that he was never really the blue eyed boy and next Wasim Akram on the scene like Amir..he has a tremendous work ethic and attitude towards the game..the way he runs in, his body language on the field, his perseverance..add that to reasonable talent and ability, and he should have a tremendous career..
Having said that, problem with Junaid is team management..he has been playing international cricket for 2 years now but has been regular? they keep dropping him for no reason for the likes of Cheemas and Tanvir Ahmeds and Sohail Tanveers... He should have been opening the bowling with Umar Gul from the South Africa series of 2010, right after the Amir-Asif debacle.
He should have played the World Cup, West Indies series and the England series.
In other words, he should have been what Umar Gul is at the moment for Pakistan, the one fast bowler we cannot drop no matter how crap he is from time to time..
I am particularly glad now that he has won Pakistan the series in India, hopefully this will do wonders for his career and the team management and captain Uncle will realize Junaid can be far greater match winning bowler than not just Umar Gul but most of the other fast bowlers in the world today..he needs to be a regular in the team..all the other fast bowlers including Gul should be fighting to retain their spots.