I'm not sure which server has the worse exp rates.... played JP server and got to level 7 in like 5 minutes and was just like.... well fuck.... compare that to the US server though and it's just like they are to two different extremes.
I would liken JP server to Time and Eternity and US server to Dark Souls in terms of difficulty

Duel ultra-greatswords with lightning/dark and resonant weapon.
stone skin/greater magic barrier for only magic spells I use because hexes are for people I 2-1 shot

Where art thou gods now?