I have noticed a small error when it comes to logging in.
When special characters are used within a password, the launcher complains it cannot connect to the master server.
The password that was causing the greif was "D4td7ktJ^$VZpk^3" - That password is unique and I'll never use it agin.
I have sinced used a password without the special characters, and have experienced no problems.
Awesome launcher btw!