On 2nd may there was a nice article on Janes about a conference that was -among other isues- about future US aquisition policy.
It was warned that in the future high-tech weapon fielding may become too expensive to afford and take too long. The speaker advertised cheaper "low-tech" systems that can be introduced faster and in greater numbers.
Also the consolidation of the defence industry hinders DoD competition, leading to less innovation and higher costs.
Looks like the lead nation now comes to a point were always better leads into a dead end.
I'm sure that China also will inevitably come to a point were buying more less advanced systems will bring more benefit than to aquire the most advanced ones. However, this point is still some time away, maybe decades.
The J-11 is a somewhat given design wich the chinese seek to improve, while the J-10 seems to be their testing product from wich on they might design comming gens of fighters. In the wake of trends to go stealthy, an IRST should also be an option for the J-10.
As regards the 2020 timeline, form my outside standpoint, I would guess a J-xx to become operational, J-11B, J-10 block X and FC-1 to be the main force, augmented by JH-7B and J-8II filling gaps.