Overall id say it this way: Pvp: arc Pve: void Allround: solar Heres why: both the void and solar sword deal the same amount of damage with their special attack. The arc one deals a lot less though. Also, if you choose a sword as your heavy weapon, youre most likely going into melee range with it. A sword isnt a ranged weapon obviously. So arc already isnt the best one to choose for pve purposes so which one should you choose for pve? Well since solar and void deal the same amount of damage but void being aoe and solar single target damage void would have the upper hand here. For pvp, the void one honestly sucks when compared to the other ones. The only time youd take your special attack over the standard attack is when someones using a super. And since the void one needs about 1 second to deal the entire damage the solar one would be better as it deals the full damage immediatly. Though the arc one would probably be the best one to go with because of its ranged attack. Having to kill someone at a distance because he would otherwise kill you happens way more often than fighting someone whos using a super

Ive got one of each in the cooker, had my void one ready for the arms day ...about an hour after arms day began... Now I gotta wait till next Wednesday to move up. *note to self: shriek at bungie over incorporating arms day into quest lines.*

choose the one you like or want the most. I went with void sword because I like the void.