We have tested before Kingwood and GT-HID, GT-HID is more brighter and bluish. Xenon-Vision and GT-HID are the same manufacturer, all the GT-HID faulty ballast after repair will sell under Xenon-Vision. The H4 bulb of GT-HID will have a front cover shield on Nov to give the light output more even, forus and no glaring problem. We also sell the front cover shield now for all the H4 bulb. Please visit www.gthid.us for more information. Thanks!pifecto14 said:whats the diff between kingwood, xenon vision and GT-HID?? Got differences in brightness??