I played both NexonNA and NexonEU games.
Their customer service is horrible (they ignore assistance requests most of the time), and their efforts ONLY target towards squeezing money out of players rather than providing a quality service.
Things are particularly bad at Nexon Europe: Their prices are the highest, but their attitude towards customers is the lowest.
I play Mabinogi Europe. They have totally ignored the game for over 1 year, often skipping server maintenances too, thus making many players quit.
In october 2011, they announced half-officially that they'd release new content in November.
So, on the 29th of november they ran a long maintenance.
They did not put any new content in the game, and they forgot to put the monsters server online, rendering the game unusable since monsters wouldn't spawn and the game mainly revolves around killing monsters.
It took them 4 days to finally notice and do something. And this is not even the first time: Once they forgot to put online the login server.
Worst gaming company I've ever seen.
Review about: Online Games.