The new GX series is under the CM Storm sub-brand. Unlike the original GX series, it does not have a hyphen in the name.
The product description of the GX550 says:
100% Japanese capacitors
Custom DC-DC module design offers higher efficiency and voltage stability
ALL black flat cable for easier cable management.
Looking at this image from the website:
and compared to this image of the G550M in the TPU review by Aris, it seems to be the same CWT platform as the GM series, with 100% Japanese capacitors (replacing the CrapXon and Jun Fu ones), but with no modular cables.