I was able to log onto Sargatanas twice today with no problems, and have been able to play on the JP servers as well.

On the other hand, I haven't been able to play on Excalibur (where my main is) since Saturday. I'm pretty sure Sargatanas is the least populated of the US Legacy servers, while Excalibur is pretty packed, but it is still frustrating. Sargatanas was pretty busy while I was on though.