C# or Java?

In reply to my earlier post asking others how they learned C#, I received a message from a reader who thought that it would be wise for me to learn Java first.

I have to admit, I never really thought about learning Java. Most if my Java experiences have been as an end user and quite frankly been pretty awful. My current employer uses alot of Java based apps and we've had performance issues, issues with one version of JRE working with certain apps and another not working with others, bizarre cross platform incompatibilities and oddities etc...

From what I understand, syntactically C# and Java are very similar and skills and methods learned in one may easily translate to another.

I'm not sure I'm willing to change paths now. What would be that advantages or disadvantages of doing so?