Build times are fantastic. Performance is still quite a bit worse than Java, actually. It has its own compiler, and so it doesn't benefit from the huge amount of work put into optimization in GCC and LLVM. Definitely not roses and unicorns.

Go has MULTIPLE compilers, because Go is a language spec, not a compiler. Hence GCCGO (which for example, takes advantage of some of those GCC optimizations) can be used.

Additionally, in most benchmarks, Go does fairly well and is young and constantly improving: http://www.techempower.com/benchmarks/

You will also find Nimrod / Jester in those benchmarks, and can compare the performance for yourself.

Pedantry. When people talk about Go, they usually mean the official implementation.

gccgo has too many issues (lags behind release, requires gcc recompile, etc.) to be useful to most people.

I disagree. I know most Go shops I have dealt with at least have looked into gccgo. We use gccgo in the wild (for all our image processing components), because it gave us a nice performance boost. With good testing, you can easily do A/B testing using gccgo to see where it makes sense for you in production.

We have to dig through 30TB of images -- so the performance benefits we got from gccgo were worth the trivial effort it took to implement.

What is "quite a bit worse"? Is that 2-3x slower? Or 20-30x slower? It's my understanding that it's the former.

And then there's memory consumption...

The former.

Go is pretty much competing with java and not C, C++, FORTRAN, and Ada. Nimrod is up there with the best of them. Go is also somewhat designed around reducing build times, nimrod is not. However C and C++ (esp C++) pretty much manage to be designed around increasing build times, so Nimrod is much faster to compile than they are.