Far more likely to damage the vertical edges of each sheet if they're installed vertically. Each nail/screw has just 3/4" of bearing on the stud (one half of the full 1-1/2" stud thickness), meaning there's bound to be some broken/crushed/torn edges, even when "angling" the fasteners towards the center of the studs. Resulting in weaker connections, prone to not resisting impact forces against the finished wall without failing.
The smart way is to take any bows out of the wall (inward or outward) before installing the sheetrock, either by shimming or trimming. If it's a room "that counts" (meaning not a closet or dimly-lit man-cave), I make a practice of carefully eye-balling the complete stud line before the first piece of rock goes on. Have even used a stringline when there are too many bad studs.