Well, looking at the work share and that China will mostlikely even manufactor the Russian designed parts. I kind of changed my opinion about this deal. This is a smart way of tapping into the once Russian owned market.
China is not the junior partner here.
If your worry were about if China would be the junior partner in this deal, well, that worry should never have been there to begin with. Anyone with some basic understanding of China's ambition and goals in the commercial aviation space, the development history in the sector and technology and industrial foundation in place would not even contemplate such a partnership.
The real question is whether and/or why China would take Russia or anyone else as an equal partner. At issue is not if Russia has some experience or technology to offer, but who drives and controls the destiny of the program. To put in another way, today if Boeing or Airbus - which have vastly superior experiences and technologies than Russia - offers China to join one of their star development programs as junior partner, well, China would probably join, but it will always have its own separate and independent development program. In fact, Airbus has and Boeing will soon have final assembly plants in China for A320 and B737, respectively. To use another example, in the '90s, Europe invited China to join the Galileo navigational satellites program, as a junior partner obviously. China contributed hundreds of millions Euros to the program and gladly became a junior member, but it still has its own Beidou program. Europe later refused to let China participate and share the core technologies development and benefits of the program, but China has been quite successful with her own Beidou system.
Some people cite the rumors that China is interested in acquiring a stake in the struggling Bombardier C-Series as evidence that China must take Russia as an equal partner in the C929 program. I think they're confusing the natures of the two. China is interested in acquiring a stake, majority or minor, in many technology companies in many industries, but that doesn't mean China's own respective industries is hanging in threads.
Back to the C929 program, it's obvious that Russia demands an equal partnership and got it, at least on paper (Note that it was never about China demanded an equal partnership and got it; huge difference). But in reality, it's not difficult to see where the center of gravity is. Shanghai has the headquarter and final assembly line; Russia get a 100 plus people R&D center, but China has separate R&D center too. The risk to this equal partnership, IMO, is not so much the experiences or technologies that Russia or China brings to the table, but that China's and Russia's strategic interests in this program may well diverge down the road and rifts inevitably emerge to create problems and roadblocks to the program.
By the way, what ever happened to the New Development Bank, aka the joint development bank of BRICS? There was much fanfare back when it was founded a few years back, where each BRICS nation largely shares equal partnership (considering both investments, shares and management controls). Well, without China's leadership and drive, it doesn't appear going anywhere, at least compared with AIIB, and the OBOR initiative.