I disagree, I would take a higher-dps weapon with lower aspd than vice-versa. When you have higher aspd, your arcane power drops a lot faster, thus lowering your overall damage capability when compared with something sustainable. I've found that using a weapon with ~1aspd or thereabouts and certain combinations of passives (storm armour w/ ap rune, crystal skin w/ ap rune) allows for complete channeling of your frost beam skill w/ the ~280%damage rune. Extremely useful for most boss fights if you have good positioning (you're able to use it against all major act bosses -- that is, butcher, belial, azmodan, diablo). If you don't need positioning, it's still better to pull a smaller ASPD weapon, as it gives you better burst from your AP whenever you slow down -- for something like this, I might use arcane orb w/ (obliterate? rune which increases damage %).
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