The inside is laid out very well, but there is one minor issue that I have to point out. To install a power supply you need to remove the top fan. Nothing major, just a bit of an inconvenience and something to take note of.
Below we see a complete system installed inside the NZXT Zero. There is plenty of room for all of your components, and working inside this case is quite easy given the space and variety of tool-less features. Once you have all of your components installed there is still a good deal of room which is nice since it makes it more visually appealing and will help the airflow keep the system cool.
As seems to be standard these days, this case includes tool-less installation features for all drives and for all expansion slots. The nice part about it is that it also works well. I have seen more than one instance of a tool-less design where installing or removing the drives and cards was more work than it would have been with screws. The Zero has none of those problems.
The below left image shows the sideways mounted hard drive cage which features tool-less drive rails to make installation simple. The below right image shows off the back of the case with everything installed.
