This has been a frustration of mine, and increasingly frequently. I get wanting to see better, but the problem with a lot of these aftermarket kits is that the really don't improve visibility that much. The problems are twofold:

Fist, beam pattern, housing alignment, and lens clarity are important. If you throw HIDs or LEDs into a reflector housing designed for halogens, you'll end up casting a bunch of light upward, high enough to be useless for long-distance road visibility at highway speeds at night. Yeah, you'll see those reflective highway signs lighting right up all right, at a distance way too far for you to even read what's on them. And if your headlamp lenses are dirty or hazed over, you could have the luminous output of the sun in each housing, and you'll still only get a slight improvement in visibility for all the diffusion the lenses are causing. You would be amazed just how much visibility you can get by cleaning & polishing your headlight lenses and making sure they that are properly aligned and putting out the correct beam pattern, all while leaving the light emitting devices themselves unchanged.

Second, the color temperature of these aftermarket kits often ranges from sub-ideal to outright wrong when considering the purpose of nighttime visibility. Most of the aftermarket kits I've seen on the road have had a very high color temperature -- very very blue, or sometimes outright purplish. Someone might think their car looks very stylish with such a headlight color, but they are actually working against how their night vision works. By my reading, the human eye is most responsive to light in the blue band for brightness perception. So, by that logic, it would make sense to turn the color temperature up, right? Well, only up to a point. Naturally, light is more bluish during the daytime. And outside during the daytime, one's pupils end up quite constricted, so not to overwhelm one's eyes. And so when someone drives around with headlights at 5000k, 6000k, 7000k, with all this bright blue light right there in the foreground in front of the car, they're actually killing their night vision, and their peripheral vision, especially. Everything in the path of the headlights might seem nice and bright, but anything outside of the center of the beam is going to be a lot harder to see than if they were running a much lower color temperature at equal brightness. And finally, in inclement weather, like fog or snow, all that bright blue light is more liable to get reflected back at one, blinding one. IMO, 5000k and up is too high of a color temperature. 3000-4000k is ideal.

I personally would love to start seeing more enforcement of the existing laws on the books regarding headlight beam patterns. Because if there isn't, then it seems likely to me that there will be new laws passed that make it harder to get any aftermarket retrofit kits or do any DIY retrofits, period, even if one's retrofit were otherwise completely compliant with the existing rule as to beam patterns et. al. I really hope that those who are being irresponsible with aftermarket LED headlights don't end up ruining things for those of us who are able and willing to do the research and take the time to do a headlight upgrade correctly, such that it is safe, legal, and actually useful.