If this agent thing works out in the time line he states it would be amazing.
It takes at least two months for a paper based application till you get final visa in Islamabad. And i am talking about engineers who already got LMO's approved with all completed documents BEFORE applying at the embassy. This is roughly from Dec 2012 - Feb 2013 time frame. In one case, it tooks just 4-5 days for the initial medical call to come, but still after submitting medical results it took two months till receiving final visa. In another, it took one month for the medical call and then another month till final visa.
It is true that i am only talking about paper based submissions, but i really doubt if online submissions take less time. Even the official canadian embassy link for pakistan states 16 weeks approx for temp work permit visa.
canadainternational.gc.ca/pakistan/visas/processing-traitement.aspx
Do let us know about your progress.