Arengar, even if you had 100 luck, the probability of a successful attack in battle would be 50%. The fact that it's more than 5 has significance only in version 3.0 when the enemy has the ability to reduce your luck. I don't level up Special Ability (SA) for either elves or dwarves.
If you don't think it's necessary to level it up, why are you praising it so much?:confused:
Added after 11 minutes
although the Haven SA is seriously underestimated here simply because it doesn't look as impressive as the others.