Having used a variety of cases over the years, from Xigmatek to NZXT to Corsair to Fractal and now Lian Li, I find the O11D the best to work with in terms of cable management space. Precisely because 99.9% of users won't use the extra psu slot, so u have tons of room to stuff your excess cables (if u get lazy) into that area as long as no HDD drives to block that area. Compare that to the usual casing layout where the most generous mid-tower ATX (some full tower even) gives you max 2.5cm of width to stuff all your cables at the back or risk forcing the back panel shut. Also the utilization of space is maximised in the O11D. Case in point - the side fan mounts provides you airflow from the back panel, where this space would usually be dead space used to mount HDD/SSD drives even in the most flexible of configurations in standard boxes like the Fractal R6. Granted, if using air cooling, O11D is too spacious, can try for O11Dmini instead. Otherwise I think this is probably the most well-thought out casing in a while (another example - don't deal with stock casing fans instead, just bring your own fans).