China appears to be mastering radar and C-31 systems quite well frankly. Whatever gaps they have on their indigenous designs, they have plugged by reverse engineering Russian designs like the Bandstand and Top Plate radars. The 052C arrays and its surface search radar (top of the mast) shows you how far gone China has gone into naval radars.
The engines is more of a question mark as they seem to be reliant in so called "imported" engines. I put the quotation marks because so called imported engines are actually made in China by foreign firms. This is especially with regards to diesel engines for subs and CODAGs for the larger ships.
Goll makes a good point on this one
Reliance for submarine based defence navy should be left behind, its weaker opponents style...but china needs naval supermacy over Asia...subs doesent bring that.
One does question however if the Teddy Roosevelt style of showing a big stick to all of China's Asian neighbors is of political benefit.
China as a policy seems much more interested in portraying itself as an underdog and a "peaceful" neighbor by always constantly understating its military. The best remains hidden, no roadmaps are ever given in public, kind of like a poker player hiding ace cards. The propaganda is useless because they only like to show people in parade and hardly ever new stuff---not like the monumental 1999 parade where the PLA actually revealed all sorts of new hardware like the ZTZ-98 tank for the first time. China appears to be very sensitive about criticisms of its miltary modernizations.
Having said this, the argument that it is now or never that China should learn to field a carrier. It is currently the only one in the UN security council without one. Was this because of a change in leadership? After much interest in carriers in the nineties, the pro sub faction in the PLAN took over, placed carrier studies into hiatus and concentrated on subs, albeit with much surface ship support. The so called phased expansion of the PLAN from green water to blue water navy envisioned in the nineties was tabled for a green navy with an underwater sucker punch. All that time, JZM seemed to be making that war with Taiwan was imminent.
Change of leadership again, and JZM is out of the CMC. That is a profound development for the entire PLA. The PLA now appears letting go of a myopic attitude of preparing for an imminent conflict with Taiwan in the near future, for longer term and more grandoise plans of developing its technological base. Back to the 1990s vision. But then with civilians and technocrats so much in charge, every new generation of Chinese leadership isn't going to have a militaristic worldview and of China's future, though they will insist they will do everything to protect China's homelands and prosperity.
This is always a tough loggerhead question as to why China should field a carrier. Many Chinese do not beleive China should do it, while others do. There is quite an opinion split here, and I bet it also reflects what is inside the CCP and PLA leaders too.