The change in PA in 1.8 can confer some advantages if you equip properly. One major change is that you get the PA bonus for each weapon of that type you have equipped. So if you have 10 points in dagger PA, and you’re dual wielding daggers, you get 40 attack power, not 20.
This means that unless you’ve got a LOT of PA levels, you should be focusing the majority of your PA points on one weapon type and making sure you have them equipped. For most, that should be daggers. The Molten Brand is easily accessible and the direct upgrade is the Soliton Blade, which is also a dagger.