I tried one LED headlight and found that it had a "black" spot in the center of the low beam, and low beam cutoff was poor to say the least.
I have found these bulbs which claim good low beam cutoff plus the typical LED specs. I have not tried them yet; they are not cheap; $250 for a pair.
Available here, and other places:
http://www.xenondepot.com/h4-philips.../12953bwx2.htm
Philips' info:
http://download.p4c.philips.com/file..._pss_engau.pdf
From this info sheet:
Philips patented SafeBeam optical design brings maximum visibility with a beam pattern that does not glare other road users. Similar or better beam pattern than standard halogen lamp, ECE beam pattern compliant*.
* There is no ECE regulation existing for LED bulbs. ECE beam pattern compliance is tested on several commonly used luminaires where the LED bulb beam pattern matches the ECE approved halogen beam pattern