If it was up to me I would have gone with full monomorphization because I don't care about binary size or compilation time quite as much as the current Go devel

If it was up to me I would have gone with full monomorphization because I don't care about binary size or compilation time quite as much as the current Go developers. However, the decrease in performance of the current implementation is being vastly overstated because people read a single article. It's not going to be even close to a bottleneck in all but the most extreme performance demanding applications and those applications probably shouldn't be using a garbage collected language to begin with.