But if that is the case, J10B is clearly the way to go instead of limiting PAF to 4th gen techs, that hardly brings them on par with IAFs upgraded Mirage and Mig 29s.
Unless the US will provide PAF with something like the F16 B60, 2nd hand F16s will only add up numbers, but not quality.
The J-10B is a financial risk, since the aircraft is still undergoing testing and not operational as such.
moreover, a J-10B purchase will come in 5 years... a F-16 purchase comes in 2.
Moreover, the F-16's will be upgraded to AM/BM standard which brings them upto block 52 standard except the integrated ECM and CFT's.
Which are still fairly potent 4++ gen aircraft.