Kudos to GIGABYTE for the M.2 slot (still no DC-in jack though). The entry-level J4005N D2P also supports DIMM RAM, a pretty rare feature for SoC-based motherboards. Interestingly, GIGABYTE also mentions 16 GB RAM max despite Intel's own 8 GB limit.
✓ Celeron J4005 (2 core @ 2.70 GHz, 10W TDP)
✓ 2 x DDR4 DIMM slots
✓ 1 x PCIe x16 Slot
✓ 1 x M.2 socket (2280)
✓ 2 x SATA 6Gb/s
✓ 4 x USB 3.1 ports
✓ 1 x HDMI
✓ 1 x VGA
✓ 1 x COM ports
✓ 1 x parallel port
✓ 1 x RJ45
