If you are new to the game or old player returning or looking for challenges.
High server: with high rated exp, gp and coins, you will easy hit max lvl as non member (225), and
High server got many op items , it's few rares cause many got them, big gigas drop from what it was before.
But if you are new, this server would be fast lvling and not much for a challenge. It's the main server on BC at the moment and you can meet new cool friends.
People care most of: gp (guild points) and Rankings.
Low server: this is a more challenging server, and takes more time to lvl than the high server .
Not many op items , that's makes them more rare, and the server is about to grow big (we hope), you can meet cool friends here aswell.
Lvling takes more time and you can enjoy each lvl instead of being boosted to 225 in hours.
I will say both servers are fun and enjoyable, but high server can/will be boring after some time.
They maybe did a mistake on raising the exp there, so in my opinion low server is like a second chance of having a great time playing and improving the game to something better :)
(Didn't know where to put this and atm it's a "copy", got it on my computer, and i fix it when i get home).
-Robo