The Corsair 2500D Airflow and the Phanteks G400A are tied in this objective comparison, as each case leads in two out of eight measured specifications. The Corsair 2500D Airflow offers a significant advantage in storage capacity, providing 100% more 2.5" bays than its competitor. Conversely, the Phanteks G400A holds a distinct edge in cooling hardware, featuring 100% more included fans than the Corsair model to support immediate system airflow.

Choose the Corsair 2500D Airflow if your build requires extensive storage expansion, as its superior bay count accommodates more drives. Select the Phanteks G400A if you prioritize out-of-the-box cooling performance, as the additional included fans provide a ready-to-use thermal solution. Both cases offer comparable utility across the remaining measured specifications, so your final decision should rest on whether your specific build configuration demands more internal drive space or immediate fan integration.