I'm located in CA and have characters on both.
Been running on POT5 as of late due to a friend getting me to play again.
I can't comment on Rated WZ teams. I gave up trying to get in a decent PvP guild that runs them. Been guildless for some time. :-/ False promises everywhere looking for a good pvp guild.
I get the same lag on both servers. It is not game killer for either, just an excuse. I do absolutely fine on POT5. It's not ping related, it is the server and game engine sucking.