I recently had to change the motherboard in my HTPC. The case is an Antec NSK2480B, a horizontally aligned case that fits up to micro-ATX motherboards.
I picked up an Asrock H170M-Pro4 to put in along with appropriate CPU and RAM. Didn't think there would be an issue as the Pro4 is a micro-ATX motherboard, matching the case. No issue, right?
Unfortunately, the Pro4 is a full sized micro-ATX board, larger on the "width" axis than most of the mATX boards going around these days. It physically fits in the case, but four of the six SATA ports are arranged so that the plugs go in parallel to the board — as shown in this pic:
In a normal case this would be okay, but the NSK2480B has a solid metal divider that runs in between the motherboard area and the drive/PSU area. The side-mounted SATA ports on such a wide board do not fit. I managed to get two 90-degrees connectors in before mounting the motherboard, but the other two ports just can't be used. The pic below shows the mounting (bit hard to see due to the other cabling):
The wall the SATA cables are pushing against is a solid piece riveted in to the case. Other than grinding out a chunk, I can't see any way to get access to those bottom two ports.
So...a full sized micro-ATX board with side-mounted SATA ports is not a good match for this case.