@akronawol17: No you're still not getting it. Haki is pre-cog and light moves in a straight line. If Luffy knows where the beam is going to hit all he needs to do is move out of the way of it because it's not going to change direction. Speed almost becomes pointless against a good haki user but unpredictable attacks like the one Luffy used against Enel can still catch them out.
Now Doflamingo and Luffy both use haki so both can predict each others moves, however the person who is better at using it has the edge. That's why I always state that haki users have an edge in battles against other verses because they can basically see the future a little.
I always mention this and it always gets ignored as though people just pretend it's not a real thing or they just choose to ignore it because they have no argument against it.