Good points to cover, for sure. ASUS software is excellent, no doubt. Layout..man, impact + add-in PCB and M.2...many tower cooler don't fit. You have MPCIe Combo II + IMPACT AUDIO cards on one side, dimms on 2nd, power PCB on third, and rear I/o towers on fourth. Wiring is almost worse with front panel plugged in. I did review this board, and do have pics.
But NOTHING OC's memory like IMPACT. IMPACT, to me, is dual-duty bench + game; that's why those add-in cards are add-in to begin with, and it has beefy VRM design. It is a COMPLETELY different product. At the same time, the idea of using mITX and having such a hugely capable board almost defeats the purpose of mITX. Using a tower cooler, eliminates many of these "I want smaller case" ideas, too. Low-profile cooler support on IMPACT is HORRID. At the same time, it's pretty poor on ALL mITX boards.
UEFI..I prefer ASUS Z87 to ASUS Z97. But there is still issues with ASUS UEFI, too. I can corrupt too easily. The stuck-clock problem, corrupted MEI, USB 3.0 problems, etc...
ASUS has done something really interesting with mITX, since they offer clocking in such a way with ROG boards...people expect a lot. I don't expect that ROG experience from anything, but ROG. ASUS has best fan control.