Things have changed since the original concept had emerged.That's a 24% increase in volume from the original concept.
I really do not see any reason why I should not choose e.g. Ghost S1 over C4-SFX. Great quality, expansible (if I need to change my cooling later) and sub-10 L in base version. FormD T1 is another great case, with 3-slot GPU support and possibly with better thermals than C4-SFX.
In my opinion this volume range is almost saturated. We need something new that these cases do not offer. In my opinion it should be either 280 mm rad or TG panels support.