Myself, my main Runearm is still
Glorious Obscenity, from the Reign of Madness chain. Being acid, it gives you a higher imbue dice (2d8 acid against 2d6 force), and have a better runearm damage. It also hits evasive mobs by being a Fortitude save (that benefit on bosses by the ammount of melees spamming improved sunder), and have seeker +6 and enhanced spot +5 (stacks with the +20 spot from pirate spyglass).
I cover my potency with the bracelet of the hound raid (potency 52 with this runearm, arcane lore, and greater evo focus in a single slot). And of course, I carry a Lucid Dreams for acid-resistant mobs (devils in general. Demons take full damage from acid)
Toven may be awesome, but you still need to run Master Artificer a lot to upgrade it to the full power, and nowadays, only other artificers want to run this raid, for the same reason. I was amazed at how quickly this raid jump off from the usual LFM weekend groups. If you don't have Toven's, there is no reason to buff your eletric line, since your most used eletric endgame spell (Lightning Motes) is most useful to give eletric vulnerability than for the damage. And every other damage spell artificers use (Tactical detonation, Blade barrier, Prismatic Strike) benefits from force enhancements.