Putting LED (or HID for that matter) bulbs in headlamp reflectors designed for incandescent bulbs is not a good idea: dispersion above the cutoff on low beam will cause 'discomfort' to oncoming drivers.
Here's a photo with an HID bulb in the left headlamp, incandescent in the right on low beam: the circled areas show what an oncoming driver would be blinded by while the right beam shows the distinct low beam cutoff line.
Test with LED bulbs showed similar results but with not quite as much dispersion.
just sayin'...
Peter