Elite Bastards posted a review on the Cooler Master ATCS 840 system chassis

Given the size of this chassis, it's no surprise to find that the ATCS 840 features some spacious internals to play with. What's more, this case even features a pull-out motherboard tray, which seems to be quite a rarity these days, potentially making upgrades, motherboard swap-outs and the like far easier.

Continuing down the "ease of use" path, it's also worth noting the space behind where you'd typically find the CPU seated on your motherboard - With the far side panel removed, this allows you to access the rear side of motherboard, allowing you to fit any CPU cooler you can think of without removing the motherboard. As a reviewer who often ends up with CPU coolers that use their own custom retention mechanisms, I can't tell you how much easier my life would be if all cases had this kind of attention to detail.

Cooler Master ATCS 840 system chassis review