I just did my first epic TR (im slow, job and family...) and decided for colors of the queen. I wanted the extra HP from primal, and wanted to try the effect. Now, at lvl 3 again, ive had some (not many) moments where it procced for about 250-500 damage which is quite nice. Since more HP are always good, I might try to get 3 stacks of this PL. Primal also has two destinies which are VERY playable, either Shiradi or FoTW will help almost any build, so it wouldnt be much of a chore.
The extra spell crit looks nice but is only valueable on certain (shiradi) caster builds since its only elemental.
It would be possible to get 27 PRR from the divine sphere but having to grind 54 million xp in divine destinies seems masochistic to me.
9% doublestrike would certainly be interesting for melee builds, but im not sure if it would be that much better than colors when active, and the passive AC wont do much when the destiny is not active.
Which epic PLs do you want to get/get first?
Iconic PLs seem nice, too, but I only have PDK so far (got a cheap shadowfell pack)