Litheor Transmutative Locator -- would you put it on an invincible planet* for a 6% bonus and a lot more artis per hour, rendering the defensive bonus moot, or would you put it on a project planet for more artis per hour and a nice defensive boost?

From the wiki, in case you were wondering:
Artifact: +6% and Defense: +10% OR
Artifact: +5% and Defense: +20% OR
Artifact: +4% and Defense: +30%


* I am assuming nobody here is making planets without majorly high artifact production invincible.

Fit them on invincible planets, of course, will bring the most benefit. But, considering that you will have plenty left after doing that, I'd still go for the +6% artifact on project planets.

IMO any planet worthy enough for it should be fully cloaked anyway
6%