The manual for the Zero 2 doesn't go into a lot of detail concerning installation however the use of the drive rails is pretty self explanatory. Simply snap the pegs into the sides of the drive where screws are normally threaded in and then slide the drive into an available bay. The tabs on the rail go towards the "front" of the drive and must be squeezed together in order to release it from the bay for removal. Enough rails are included to fill every spot in the case.
A full-size ATX board takes up most of the available real estate on the motherboard tray, leaving only about an inch gap at the top and front. Because the tray is solid and extends past the drive cages this leaves little room for running cables. There's a small area behind the two 3½" external bays to possibly hide some things but again this is not easily accessible from the back side.
There is a good bit of seemingly wasted space at the top, between the motherboard and power supply. Although the Zero 2 dimensions are roughly square, the front bezel takes up several inches of the depth and as we saw in the pictures above that room doesn't transfer to the inside of the case. You will likely need a power supply with some fairly long SATA cables as well to reach the drive cage at the bottom front. Depending on the length of your power supply you may or may not be able to use the blowhole. This Ultra XVS 700 PSU just barely clears the mounting holes and installing a fan will interfere with some of the modular cable connections.
Let's wrap up this review with some final thoughts.