I understand this, but my ACOG is mounted where your MBUS is mounted. If I put the ACOG in the same location as yours, then I do not have a clear full view through the ACOG unless I move my eye closer and then the cheek weld is not there.
The eye relief of the 4x ACOG is too short. The 3.5X is probably best but it's a huge optic. I find the 3X to be the best compromise. Your experience may vary - as does everyone's vision.
"Buy once, cry once; or not. Let's be honest for a second; most of you will be zombies one day and I'd much prefer you be zombies with crap weaponry."