Waiting for this mobo & was wavering between tower cooler & AIO, but believe the AIO will be better for airflow – your experience seems to prove that out.
FYI got an email that In had a tracking number on the 25th of September – the link/number never worked, aways just said "A web error has occurred". Came home today & it was on my doorstep (USA).
FYI the Crosshair Impact manual is on the ASUS site now & it lists that the front panel audio connector is on/part of the audio card, so if you were counting on removing the card you won't have any front panel audio.