Today I installed CD smoke fillerz and taillight.They look great and plenty bright.I have no regrets.

 

Interesting question. I never went for these since, although they may help direct light, they obscure what is viewed laterally by the profile of the clear plastic lens. From the side, one can't see through chrome. I have seen these lenses also with slots on the sides, but they would still block some light.

 

I smoked all of mine. When I do the lens, I switch to led bulbs. When finished, it's brighter than the OEM. Do it!

 

Switching to LEDs regardless of the type of lenses, red, amber, clear, or smoked, is much brighter than the OEM bulbs.

However, when I changed my front turn signals to Custom Dynamics ring/amber LEDs, I I initially used smoked lenses but I just switched to clear. There was a discernable increase in brightness using clear vs smoked. Having said that, if you really want to use smoked for looks, I don't think the difference warrants making a change to clear.