It's easily the lamest of the 3.
It only does single target damage. The void sword can match the same damage while also being an aoe which gives you damage resistance and kills mobs all around you.
Arc sword is a ton of fun in PVP.
I can't see a place where the solar sword excels at.
Solar is a captain killer but then again the Void sword does the same thing + AoE like you said.
I said it before and I'll say it again, in PVE, the Void sword is the best.