I have used almost all 3G in Lahore/ISD/Peshawar region. So far, my experience is that Telenor is the winner, based on wide coverage and good speeds. Altough Zong gives very good speed in islo, however coverage is limted. Ufone internet is slower side. Mobilink is good but coverage not as good as Telenor.
This will change, but my experience so far..