HID bulbs in a reflector housing are just a bad idea and poor decision. HID output needs to be focused by a projector and have a cutoff to avoid blinding oncoming traffic.
is offering you is a HUGE performance gain in lighting output. The single HID bulb in the OEM projector has a cutoff shield that drops out of the way of the light beam when the high's are called upon. No warm up time, no halogen high beams, just lumens...and lots of them.
Please spare those coming at you and skip the HID bulb in halogen reflector buckets. I know that it's "cost effective", but it's just wrong.