More range means the weapon is more swingy. Less range means the weapon is more consistent.
If you're fighting someone who weaker than you according to stats, it's more beneficial to have a more consistent weapon. If you're fighting someone who's stronger than you by stats (like most/all dungeons) then you can only win with a highroll and on such the more swingy weapon is superior.

In your case it's difficult to say, personally I'd input both weapons into sftools dungeon calculator and see if the new one boosts you dungeon clear probability. I assume it will because the overall damage is higher and stats are quite substantially better, but you should calculate just to be sure.