I now have characters on both the Euro and the US servers, but after only a few days on the US server I'm thinking of scrapping my char and sticking with Euro.
In only a few days I've found that my game crashes a minimum of twice a day, I have lag issues, occasionally Game Menu commands won't work - most especially 'Voice Chat' (I like to turn the voices off) - and sometimes a Skill I've added will disappear from the line along the bottom of the screen.
On the Euro Server my Weapon occasionally Glitches and I'm unable to attack, but it's easily fixed by running a short distance away and sheathing my weapon.
Why is there such a big difference in the performance of Servers?