Here's the thing:
If 8000k lights worked better than ~4800k bulbs, that's what all of the oem hid bulbs would be stock. But they're not. The range between 4-5000k is the closest to the accepted value for natural sunlight. This means greater visibility and less strain on your eyes at night, and more importantly to the people driving at you. I had an oncoming asshat the other night with green HIDs and I wanted to run him off the road. Burn temperatures above 5-6000k start getting really irritating to the eyes. Plus the actual light output, in lumens, is reduced.
Not only that, but relying on the cheapest possible Chinese knock-off technology to power one of the most important safety features on your really nice new expensive truck seems a bit careless. I, personally, spent upwards of $1000 buying new housings, retrofitting Acura TL projectors (unfortunately missing from the early 5th gens, but also important for proper HID setup), and installing OEM Denso ballasts from Lexus with oem Phillips 4300k bulbs. The output is phenomenal, I never get high beamed, and I'm not going to look foolish when my knock off ballasts catch fire under my hood. You've got a nice rig man, spend the money, do the research, eat the $30 and buy some real equipment. The retrofit source is a pretty good resource for this stuff.