If you look from investment and profitability both are good. I would suggest I-16 with I-16/2 and I-16/4 in particular. In real estate, things are not black and white so all aspects must be considered such as:
1. CDA vs Private Developer - One is an autonomous Govt. Agency while other is a private developer offering a luxurious living. On a worst case scenario Govt. (theoretically) will not default to its customers while a private developer can and has many times.
2. Utilities and Amenities - I-16 is a developed sector with Electricity, Gas, Water available with 100% possession available of each plot and commercial in Markaz has been auctioned. Many families already living there with direct connection to I-15 & I-16. Park View City (PVC) is getting in shape with a luxury life style but atleast 5+ years to be properly live-able. IESCO just approved providing electricity but no idea about Gas as yet.
3. Location - If you take Zero-point as a benchmark PVC is 22.2 km with 35 minutes drive from it. I-16 is 20.7 km with 33 min drive from Zero-point. Access of both will improve in near future.
4. Surroundings - PVC Surroundings are Bahria Enclave, Park Enclave etc. I-16 has locality is I-14, FOECHS, CBR-2, Taj Residencia etc.
5. Pricing - In PVC Possession plot of 5 Marla may touch 50 lac whereas in I-16 possession plot ranges from 30 to 40 lac. But keep in mind, PVC possession plot will only become attractive once Electricity, Gas is available and area is livable. PVC spends heavily on Marketing and Promotion so that money must be recovered from customers.
6. Construction in I-16 can be cheaper than PVC and generally CDA property brings more rental value.
These are some of the points, there can be many other aspects that I already shared regarding PVC and I-16 on different threads so may be a quick search can help you to read details from other valuable and knowledgeable forumers here.