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.
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.
gccgo has too many issues (lags behind release, requires gcc recompile, etc.) to be useful to most people.
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.
And then there's memory consumption...