The Lian Li O11 Vision is the objective winner of this comparison, securing more category wins across the evaluated specifications. Its most significant advantage lies in its support for power supply units, offering a 19% greater maximum length compared to its competitor. This increased clearance provides more flexibility for users installing larger, high-wattage power supplies, ensuring the Lian Li O11 Vision accommodates a broader range of hardware configurations than the NZXT H9 Flow.

Choose the Lian Li O11 Vision if your build requires the extra internal space needed for longer power supplies. Conversely, the NZXT H9 Flow is the superior choice for users who prioritize out-of-the-box cooling, as it provides a 100% advantage in included fans. By selecting the NZXT H9 Flow, you eliminate the immediate need to purchase additional cooling hardware, making it a more convenient option for those seeking a complete thermal solution upon assembly.