the beam pattern is not effected as that is to do with the lens on the head lamp not the bulb
st10587 always says to get them from the diana shop on ebay as there £35 so i thought id say before he does lol. i already owned mine before i knew that but i suggested them to my mate and for £35 you cant go wrong there a quality bit of kit so theres 3 people giving good feedback for them straight away.
try them you wont be dissapointed especially for the price.
right in principle but not strictly correct as halogen and gas disharge produce light in different ways the refelctor deals with the beam differently also usually scattering it as it's reflected off the wrong angles
projector lights will produce the correct beam pattern as the light is processed as it were but a standard rear reflector only will not