Haven't tried zong since long. Will try after couple of months.What about Zong?
Ufone on the other hand has 15 MHz contiguous spectrum in 1800 MHz. And their data users are very low because their super card users are not extreme data consumers and their other packages are also expensive. So they have enough free spectrum. I tried their 4G all over faisalabad and in other cities as well and it provides minimum 30 Mbps average speed which is great. Even at my hone their 4G coverage is not available (which according to their 4G coverage map is available and I complained in PTA for misleading coverage maps) still their 3G which I hardly use due to home wifi provides stable 10-15 Mbps speed.
Zong and Jazz 3G has gone bad to worst in comparison. So going for full Jazz monthly super duper package I split my usage between Jazz and Ufone by subscribing Jazz mahana bachat offer (150 Rs. Because my 90% calls are on Jazz) and Ufone 9 GB monthly data package in Rs 550 (also 9 GB for 12 AM-9AM). And I am very satisfied right now.