I have a 2018 and compared to my Wife's GX460's LED low beams I could no longer put up with my halogen low beams
Did a lot of research trying to figure out what is best for this stock halogen projector setup and I ended up getting a Xenon kit from Headlight Revolution.
Based on research Xenon works better in a halogen projector housing as it has the "hot spot" you want as compared to LED which deliver a non focused beam. Both require a ballast so I figured lets go with the experts here and do Xenon.
Install was pretty simple, took about 1 hour. The only tips I can provide are:
1. The ballast fits nicely just above the inner fender well, tuck behind the plastic shroud.
2. Use a bit of silicon to ensure your new retrofit is a tight seal as to not let any air/moisture/dirt around the seal to your head light housing.
3. Adjust your low beams down a bit, don't blind people
I purchased the following from Headlight Revolution, with their lifetime warranty you can't beat it.
2014 - 2018 Toyota 4Runner Low Beam HID Headlight Conversion Kit GTR Lighting
(Ballast Power: 55w 5,000 Lumen, HID Bulb Color: 6,000K Diamond White)
Definitely get the 5,000 Lumen, not the 3,500 Lumen. If I were to do it again would probably go one mark lower on the HID Bulb Color, one step down from 6,000K which is 5,000K.
The result is a fantastic night drive experience, it's been 6 months and nobody has flashed me. Behind the wheel it's night and day. As a comparison to the GX460's LED's, yes mine are brighter.