I guess I'm just saying, Go's syntax and semantics aren't enough of a win for you to deal with the performance hit you take compared to Java. So use Java. It's not a moral issue.
a) writing in C for performance (and having to setup glib et al to make it comfortable)
and:
b) carrying the JVM with me to run something.
(And, no, I won't consider AOT compilers for Java. I want to deal with reasonably mature and widespread technologies and tooling).
So, there are my constraints. Given those, maybe C++ is the ticket. D is not mainstream enough, and Rust I've played with and I like very much but is still in flux.
Let's be specific. What are you building or considering, where your current options are C and the JVM? How does Go fall down on that work load?
I've got a fair bit of professional experience in both C (~10 years shipping code continuously in it) and Java, and I've spent the last couple weeks in Go --- not long enough to be a true believer, but enough to have some practical experience.