I don't know about Go, but it certainly is as fast as Java. And it can definitely be faster than your average Java program, because you will have a really easy time doing concurrency. That is why it is a neat language, worth investigating.

It is by default slower than Java and Go because the default data structures are immutable. When execution speed is more important than statelessness you can make your data structures mutable.

Read more about that here http://clojure.org/transients

Happy holidays :)