Hidden benefits of ashland weapons?

[Draconis]

So I just tried the Flamemetal mace the first time now and... well, NOW I know of what a knockback anyone speaks here. That is not comparable with the nockback of any of the former maces and definitely something I did not expect.

Are there other more or less hidden benefits on other new weapons? Just curious...

Nidhögg doesn't seem to have one, but the usual sword bonus (no damage penalty on hitting multiple targes) is quite nice already (and a reason why I tend to like swords).

There are some things already guessable from the numbers, e.g. Slayer does benefit more from bloodstone (because of it's higher base damage and... well, less defence means you are with lost HP most of the time actually), or Berserkir Axes with jade or iolith, because their attak speed mean they trigger the gem effects a bit more often...
But is there another thing that is as unobvious as that huge knockback (or better: foe-throw-away) on the flametal mace's secondary attack?