- video cards over 278mm may block drive bays
means some of the bays where you would place your sata HDD o DVD drives could be bloocked by the extra length of the video card making the bay unsable ( not a problem if you only have one drive or a small video card.
- M.2 slot #1 shares bandwidth with a SATA 6.0 Gb/s port. When the M.2 slot is populated with a PCIe-based M.2 drive, two SATA 6.0 Gb/s ports are disabled.
if only using a sata HDD then no problem if you use a M2 SSD then one of the sata ports becomes unusable - just plug the sata drive into another port. if using APCIE M" bord you effectively loose two sata ports and therefore the option of using more HDD drives