What about in a situation like this? For example, a .223 Remington - 52 grain Sierra BTHP MatchKing launched at 3,240 feet per second experiences 123 inches of absolute bullet drop at 600 yards. A .308 Winchester - 175 grain Sierra BTHP MatchKing launched at 2,580 feet per second experiences 127.6 inches of absolute bullet drop at the same distance. This would generally lead people to define the first cartridge as the "flatter shooting" of the two at the specified distance.
However, if the shooter attempts to estimate the distance and makes an estimate of 590 yards, he would shoot 3.9 inches low with the .223 Remington and 2.8 inches low with the .308 Winchester if he was able to zero each in at 590 yards.
This is, of course, neglecting to factor in that he must make adjustments in increments of what his scope allows. Let's assume he makes 1/8 MOA adjustments and was originally zeroed for 200 yards. With the .223 Remington, he would make 65 clicks and still hit .1 inches high at 590 yards. With the .308 Winchester, he would make 67 clicks and hit .2 inches low at 590 yards. The interval-induced errors of.1 and .2 inches actually fall on the side of the.223 Remington in this case since the .223 Reminton is hitting slightly high, the .308 Winchester is hitting slighlty low, and the target is farther away than was estimated (It could have every bit as easily fallen on the side of the .308 Winchester, except that is an entirely different matter that merely muddies up the issue). However, since the target was actually farther away by 10 yards, the .223 Remington will strike 3.8 inches low and the .308 Winchester will strike 3 inches low. If it wasn't for the "issue muddying" errors induced by the limit of 1/8 MOA adjustments on the scope, the result would have been 3.9 inches low for the .223 Remington and 2.8 inches low for the .308 Winchester.
This results in a situation where the bullet with the least amount of flight time, and corresponding bullet drop, actually allows the shooter less tolerance for error in approximating the distance to the target. However, in terms of the number of clicks on the scope the .223 Remington only requires 65 clicks and the .308 Winchester requires 67 clicks.
There is yet the issue that I counted a MOA adjustment on the scope as making an adjustment of 1.047+ inches, as opposed to 1 inch. I'm not sure if this is correct. Also, I assumed standard atmospheric conditions and strict adherance to a specific Drag Curve (probably the wrong one actually) with a static Ballistic Coefficient. Still, the point is that the bullet with the least amount of bullet drop and typically greater MPBR is not neccisarily the one with the biggest Danger Space at longer range as a result of the fact that the parabolic trajectory of a bullet is not a pure parabolla, except a changing one and some change differently than others.
In Summary, what do you feel is more significant, absolute bullet drop, number of clicks on the scope, or increased Danger Space?