Depends on what are you "exactly" asking does it? For example: "Is it more fun?" or "How to do the most DPS?".
DPS wise you can go frost with 2h Starshatter or DW with Elegon 1h normal + 463 on your average MGV run your dps will be almost even. To maximize your DPS I would say go for the 2h when you stay mainly on the boss with few adds in the fight, like Elegon for example, while on other bosses you should go DW for more AoE.
And on the fun part, just test it out. You might not like DW rotation for example or you might find all frost rotation not enjoyable, then go 2h unholy but know your DPS will never be the max your character can output.
In term of DPS on this tier, yes it will. If you can get another Elegon axe it will definitely be a no doubt improvement and your frost spec DPS will beat your unholy one in almost all encounters. That of course assuming your playstyle with frost is on pair with your unholy one.