The NZXT H9 Elite (2024) is the objective winner of this comparison, securing more category victories across the evaluated specifications. Its most significant advantage is the inclusion of 2.5" drive bays, which offer a 100% increase in capacity compared to the alternative. This hardware configuration provides a clear edge for users who prioritize internal storage expansion and component mounting options within their chassis design.

Choose the NZXT H9 Elite (2024) if your build requires extensive storage support and you value the superior bay count for your drives. Conversely, select the Phanteks G400A if your primary goal is cost efficiency, as it maintains a 67% advantage in MSRP. This makes the Phanteks G400A the more economical choice for builders who prefer to allocate their budget elsewhere while still meeting essential case requirements.