I have learned to do both but like others have said, it depends on the situation.
-In High Power Rifle during slow fire stages where I have 1 minute per shot, I dial. If the wind changes, I can wait for it to come back to what I have dialed. My tactic is just to watch the flags and shoot when they're in the same condition that I'm zeroed for. For rapid fire, I dial, fire my first two rounds, check the impacts and make an adjustment if needed, and fire the other eight rounds. If I sense a wind change, now I'm only holding a small amount, usually inside the X or 10 ring.
-In practical precision rifle (PRS, NRL, etc), It really depends on how many target ranges are in the stage. If the stage has one target, or multiple targets close enough in range: Dial. If the stage has multiple targets at different ranges, I may dial on the close target's wind and that way I'm only holding a small amount for the farther targets. If I have time, I will dial for all.
I've shot these matches with both gen 2 mildot and H58. I really only use the Horus for correcting follow on shots if the first round missed.
-That's all for Optics with target turrets. With Iron sights in High Power, I have learned to hold about 1MOA but no more than that accurately. With optics using a BDC reticle, hold since the turrets are covered or not they're not meant to be used like target turrets.
BLUF. I prefer to dial, and if given the time dial for changes. Or, dial initially and that way hold a smaller amount. The real key is minding the wind for each shot.