Originally Posted by mynameistory

Projector headlights have a cutoff shield as part of their design, so lights will always have a crisp line. Part of the design also lets a small amount of light leak above this cutoff in order to gently illuminate reflective surfaces like street signs and plow markers. This is why some users of HID kits in halogen assemblies are still glaring to other drivers, even when aimed properly. Because the HID capsules are 3 to 4 times brighter than the halogen filaments, this designed uplight is also 3-4 times as bright above the cutoff.

With LED drop-in bulbs, the chief problem is lack of focus. This is because the little chips mounted on the heatsink blade cannot be shrunk as small as a halogen filament, which is what your projector assembly relies on to correctly focus and project the headlight beam far into the distance.

The LED bulbs are often indeed brighter, but what you've gained in near-field vision, you have given up in distance projection. That is, the ground thirty feet in front of your truck is brighter, but the focus is now washed out and you've lost critical distance vision at highway speed. It's like riding a bike and looking at your front tire- by the time you see the open sewer you're already falling in. Check out what Daniel Stern has to say on the subject:
Why Most LED Headlight Upgrades Don't Really Work: An Expert Explains

Unfortunately, no amount of cool marketing can change the fundamental geometry needed by your headlight assembly to project light correctly. LEDs need optics that are properly designed for them, not shoehorning them into halogen assemblies. Many symptoms of this poor implementation are sold as "features". Would you buy a light bar that needed computer fans to work properly?

Take a look at this thread here, there is a lot of information that will save you money. I went down the drop-in LED road too. I am back to halogen for safety and driveability. I can also pick up a pair of H9 bulbs at any auto parts store for $12, instead of waiting on mail-order when one of the fans burns out or the chipset falls apart (as mine did).

3rd Gen HID vs LED vs Halogen H11 projector headlights | Tacoma World