One of the headlights looks dimmer and not as bright as the other one, yet it looks like all the bulbs are working correctly. Anyone run into this issue?

 

Swap bulbs and see if the same side is still dim. Usually it's the bulbs that get dimmer with age.

 

I had the same problem, and I ended up replacing the ballast to fix the problem. Just like GSteg stated swap the bulbs around to trouble shoot the problem.

 

Just curious Alainis300 where did you purchase your ballasts from? I have a GS430 and they come with factory ballasts already installed in with the stock HIDs. What brand ballasts did you use and how much did you pay?