After making this post I had a thought, and tested it.
Turns out agility has been broken since release and nobody noticed.
For the implications on the equipment meta, this means that:
- Logarithmic stats are probably +20% for 50 score. A full set is +50%.
A dull amulet is about +15%, with a matching enchantment it’d be closer to +20% (though that’s stupid because you should have enchanted it with power or defense). - A sunken iron helmet is about +5% magic size, full sunken is +20%.
- Agility is effectively half all these values - a full agility set is ~25%, an agility amulet is ~10%.
I wouldn’t recommend an agility amulet, but speed or magic size amulets may be ok as a third accessory slot. The log stats still don’t compete with power and defense.