I have used a scope with 1 MOA adjustments out to 1000 for several years. But only because it's issued. I'm not saying you can't be effective, but it takes a little more situational awareness (paying attenion/ whatever you want to call it) to what you are doing. If used for dialing you will still more then likely have to use some type of hold off (then probably just guessing at that). The further out the target the more profound.
Ex's, shooting my M24;
1000 yards:Turn the BDC to 9+2 and hold 1/2 MOA @6 o'clock or 9+3 and 1/2 MOA @ 12 o'clock. It happens to fall about half way in between. At other distances I use the high or low hold depending on which is closer.
A stationary iron maiden on our UKD range @ 734:
7-1 (BDC), hold crown (top) of head for center mass head shot.
We also have the added disadvantage of having BDC's that don't match our actual ammo and being for meters and most our ranges are in yards. We just look at the BDC as numbers for reference.