They're bright even being cool white. I have the white bulbs in my map light mirror, but amber and red in the side markers.I did see your pics. That is where I learned about them. So you are saying the regular Sylvanias are the same brightness as the ZEVO? I usually judge by the Kelvin number- 6000 at least.
I guess it comes down to if you wanna spend the extra $$ on the bulbs or not.