The PCIe riser can be installed in three (3) different positions. There are four (4) PCI brackets, and you can mount the riser to use either the bottom two, middle two, or top two PCI slots. (You can hide 2.5” drives behind your GPU if you want, and have the right cables)
With all of the exterior panels removed, installing a system is a breeze. With the hard drive cage installed, GPUs up to 190mm can be used. Removing the hard drive cage allows you to have a GPU up to about 250mm.
There is a nice cutout that’s almost the entire width of the ITX motherboard, for running cables.
There are three (3) possible locations to put the PSU bracket, and there are four (4) rubber bumpers to prevent vibrations. I wish there was a vent cut out here, so I could mount the PSU with the fan down but still get ample fresh air.
I found it very difficult to install the PSU with the top panel on (and even more so having a radiator and fans installed). Easiest way would be to mount the PSU with the top panel off.
Speaking of the top section, Lian-Li claim that it can support a 240mm radiator. It fits a Hardware Labs GTS 240 perfectly (with absolutely no room to spare on the width.). There is room for radiators 300mm long and 130mm wide. The radiator and fans (combined) can be up to 60mm thick.