As someone who writes Go code professionally, I find Go code to be really easy and quick to write, with fewer bugs/LOC than any other language I've used. Both compilation and execution speed are really fast, so you have both quick edit-compile-test turnarounds similar to a scripting language while having the execution speed of native code. Not quite as fast as C and C++, but getting there.

Writing concurrent code is incredibly easy with the primitives Go provides: goroutines (think of them like green threads multiplexed to 1 to very few OS threads) and channels (similar to pipes). No more faffing around with details of thread creation and teardown or an unreadable mess of callbacks (like you would have in system with event loops). So, if you've written concurrent software (like network servers) before, check it out, you will enjoy it.

While I don't have any first hand experience with Go's performance - it is not that hard to believe it will be fast enough - it is a compiled language, so no interpreter / JIT overhead like Ruby / NodeJS. Plus they try to be closer to C where it makes sense (it has pointers but no pointer math for e.g.).

The synthetic language benchmarks also put it very close to gcc -O2 C performance. About the only things that need to be improved further (so I've heard) in Go are the GC, coroutine/thread scheduler and crypto performance. They are already better in 1.1 release but Crypto is still not close to OpenSSL performance.