After 14 Test matches, both have almost similar bowling records, with Junaid having a better average, economy rate and more 5 wicket hauls. Amir though has a marginally better strike rate and one more 4 wicket haul than Junaid.
What MUHAMMAD AMIR did:
He mostly bowled against England and Australia, two of the best Test teams at the time. However, he took his wickets on pitches conducive to fast bowling, in New Zealand, England and Australia, with M. Asif keeping the batsman under pressure at the other end and an experienced Umer Gul also playing a supporting role. Amir took 19 wickets from 4 matches each against England and Australia, six of those 8 matches were played in England.
What JUNAID KHAN has done till now:
He has taken all his five wicket hauls against Sri Lanka, two in UAE and two in Sri Lanka. 34 of his 50 Test wickets have come against SL, in 7 matches. Although SL does not have the best batting line-up, but they have generally done well against Pakistan at home and also in UAE. Junaid also did not have any experienced fast bowlers to help keep the pressure at the other end, and he has mostly taken wickets on placid tracks conducive to spin. Although he did play in South Africa where he took only 6 wickets in 3 matches, he can be forgiven since SA batting line-up consists of batsmen with a collection of over 110 centuries among them.
CONCLUSION
After what Junaid Khan did against the in-form and world beating batting line up of India on those juicy pitches in the ODI series, we could expect something special from him on away tours in England, New Zealand and Australia but there aren't any scheduled before 2015. We''ll just have to make do with Amir's youtube videos till then.