People also seem to underestimate the performance difference. Sure, Go is around 20% slower than unoptimized C/C++ (at least, with a numerically heavy algorithm

People also seem to underestimate the performance difference. Sure, Go is around 20% slower than unoptimized C/C++ (at least, with a numerically heavy algorithmic trading library I use that I've ported to Go). But when I use a great C++ compiler that vectorizes and gives me hints to improve cache performance (eg; Intel's compiler) it's often 2-3x slower. In a tight loop, you can't afford to have a gc or green-threads or a runtime for that matter. You want excellent cache performance, minimal context switching, and very predictable memory access patterns. Manual memory management is here to stay. Don't get me wrong, I love Go (for the right uses) but it's just never going to be a replacement for C/C++/Fortran for high performance code.