Both are [i]phenomenal,[/i] though I (personally) prefer Void. I simply choose void over solar because I prefer the mechanics of the super, one and done. I never cared for timer based supers (hunters), and this is what pushed me from solar. Personal choice aside, it depends on the conditions surrounding the activity, like all other scenarios. Enemy weaknesses, what builds, ads or boss? These aren't essential questions, but can be very beneficial to creating an ideal build to suite the role you've been given or given yourself. Bloom and annihilate on void are great for ads, though vortex nova and mastery support DoT play-styles. Paired with discipline, Hunger effects can give you many grenades for a joyous time. Flame shield and radiant skin on solar soak up damage, while radiant will and gift of the sun help you get the most out of radiance. Fire-born is also immensely useful for unexpected wipes in the nightfall. It all boils down to how you play and what you think you need.