The OEM reflector style ones are mostly fine, IMO. It's the projector style lights, and when people jam LEDs in a reflector that wasn't meant for them, that are the problem.

These are the projector lamps: They rely on a little piece of metal covering the top half to keep the intense and evenly diffused light from blinding you, which doesn't work if you're not on flat ground.

Reflector style led lights diffuse the light unevenly, no differently than halogens, other than the color temperature.

The absolute worst are when people take led bulbs in jam them in headlight housings that are meant for halogens. The light doesn't leave the bulb in the same way affecting the diffusion pattern, plus they're more bright than intended.

The new matrix style LEDs could be a game changer. They allow some of the lights to turn off when there are oncoming cars, and darken just the areas where they are. The only downfall is the computer hardware needed, but the same hardware that tracks cars for automatic emergency braking systems can do it. If past is any guide, those systems will be mandatory in new cars at some point.