Since the Z97 M8 is made by ASRock, it obviously got an ASRock board as well. The Z98-M8 was specifically designed to be used inside this case, having all the required features and nothing else.
The Z97-M8 board is just a small part of the case, but it holds most of the features, all nicely fit into the mITX form factor.
The back panel has eight USB ports, split evenly between USB 2.0 and USB 3.0; analogue and digital audio ports, DisplayPort, HDMI, LAN, and eSATA all round things out. The board also uses a specialized plug for the power cable that snakes through the case to the PSU in the front.
The PSU is by Enhance, sporting a huge capacity of 600W in a tiny little box cooled by a single fan. That fan can generate a fair amount of noise when the PSU has to cope with a high load for an extended time, though it held up pretty well without becoming annoyingly loud.
The board's VRM section features 6 phases for power delivery to the CPU, four on one side and another two on another, by the 4-pin EPS connector. The Intersil-based design is fairly robust, ready to support a wide range of Intel LGA 1150 CPUs (including XEON CPUs!). The MOSFETs don't have any cooling on them, so you might want to provide them with some added airflow if your intent is to install and seriously overclock a 4790K.
There's an ASMedia 1442K TMDS chip for all HDMI signals, while audio duties are covered by a Creative Sound Core3D CODEC, which easily supports 7.1 audio playback.
The slim disc-drive is DVD/CD only as it unfortunately doesn't support Bluray, hidden up above the PSU and inside a bracket with enough room for an additional 2.5" drive should other such installation possibilities not prove enough. The Lite-On-built unit is more than enough to meet the needs of many users, but I would have preferred a Bluray drive myself. The Wi-Fi controller, on the other hand, is a 2T2R WiFi 802.11 ac + BT v4.0, so you can draw wireless signals from a wide variety of devices, as well as wireless Internet.
The wired LAN controller is by Intel since that's what a large portion of enthusiasts ask for. Even the CMOS battery's location, close to the LAN controller, is geared toward enthusiasts as it is easy to remove with its vertical-to-the-board orientation. And, for those enthusiasts that like to use a lot of drives, all six of the Z97's SATA ports are enabled here, so you don't have to worry about only having four plugs and limited connectivity like on some other mITX board products.