I had G4 for a few years (just sold them recently and bought g5s). If you get a set of G4s that don't have hyper flash or water leak issues, they are plenty bright. Mine were tinted very dark and the light output was very noticeable when the brake was applied. I made the switch to G5 tails however because I like the overall look of the design over the G4.
And as mentioned above, anzo and eagle eyes is the same product, with anzo just being overpriced. No quality difference.
And as mentioned above, anzo and eagle eyes is the same product, with anzo just being overpriced. No quality difference.