Dear Sirs:
I think the differences between the 051C and 052C reflect the relative technological differences between their two constructing shipyards, namely, Dalian (which is under the direct supervision of the PLAN Northern Fleet command) and Jiangnan/Hongdu (which are commercial yards that also build warships for the PLAN).
Clearly the 052C's (as well as various other, commercial vessels built in the Shanghai shipyards) have a higher level of technological sophistication than their Dalian counterparts.
They also reflect more domestic Chinese technological input, with hull design being just the most visible aspect.
All in all, Dalian's effort is both more conservative and modest, as well as a little disappointing. The hull form is basically an enlarged and modified Luhai (DDG 167) type, will far less provision for stealth than the 052C.
The weapons and sensor systems of the 051C are basically dated Russian designs, the only visible domestic systems being the C-803 launchers and the Type 730 CIWS.
The advantages of the Shanghai yards came about through the political patronage of the so-called Shanghai clique of ex-President Jiang Zemin. These advantages will remain so long as Dalian is not upgraded, (though I understand this is already taking place).
Nonetheless the construction of three types of large DDG's over the past 5 years indicates that the PLAN is still in the process of developing its' surface naval technology and designs.
Best Regards,
Dusky Lim