I really don't get the disappointment personally. Well, I can sort of get behind the disappointment with propulsion, but other than that...
I mean what do people want to see? Let's say there's a 054C that comes out tomorrow. What would people want to see on it to be "satisfied"?
Overall:
Modern bridge facilities with panoramic 360 deg data projection;
Improved local passive protection for bridge/CIC;
2 Distributed masts with X/S band sensor field;
Fuzed upper hemisphere visible/nIR/mwIR sensor field with backup targeting;
Modern silencing and higher speed silent running, ideally fully leveraging IEPS;
Flexible reserve propulsion(batteries, reserve power sources able to propel ship via IEPS).
DEW installation;
Hardkill TPS;
Integrated last ditch, low power requirement drone detection and hard intercept installation, ideally safe even for port calls.
Ideally, either integration of 555 into H/AJK-16, or integration of HQ-16F into UVLS.
Size, VLS requirements otherwise - depending on what 054C is meant to achieve. If it's just a next frigate in the line - this is it,higher requirement can be skipped or even toned down(555 doesn't sound all that much worse than HQ-16C, and we remember noises about quad-packed light VLS ASCMs); in this case, just 16 compact UVLS cells can work out and still provide net capability gain over 054A series.
If it's replacement for 051bc/052(b)/956e(m) - ideally, increased weapon fit with 16-24 full depth UVLS cells and ~24-32 ones able to accept HQ-16F missiles; flag and improved processing facilities.