Well at the risk of being simplistic the J-20 is a very ambitious project for Chengdu, and much is riding on its success and eventual adoption, so I would suggest that as an indigenous Chinese aircraft it enjoys unprecedented political support. It seems to be moving "forward" very nicely at a very pragmatic and helpful pace and I expect to see it go LRIP very soon.
Compared to the F-35 it is of necessity going to be progressing at a slower rate as it is not as far along in its development, the F-35 is a driven project, with LOTS of MONEY and Political support, even more so than the J-20. There is a much stronger market in the general public for the F-35, as there are a great many more military enthusiasts in the general public, who have a more mature understanding of "stealth"
On the opposing hand we have the PAK-FA or T-50, again a very fine and ambitious aircraft for Sukhoi, it seems that funding is problematic for the T-50, and that several serious development snags have been impeding the forward progress as well, one of reasons (maybe the only reason?) that the Russians are now opening up this project and inviting the Indians onboard for a much more important role, and in fact are willing to taylor a version of this aircraft to the specific Indian need?
So to cap it off, the J-20 seems to enjoy broad political and popular support, as well as the engineering and finances to keep it moving forward. It seems to be meeting all the developmental milestones and performance objectives, so all in all I would say the Chinese are very tickled with their overall progress on the J-20.
I would conclude by adding that president Xi seems to have pushed this ahead of the indigenous carrier at the moment, but we shall see??
While J-20 program "seems" to enjoy top level support from the Chinese leadership (we don't really know for sure, for example the first J-20 "reveal" back in 2011