Go does lack a quality [IMO] IDE [re: REPL use is for development], but that can still come with time.
Quality GUI bindings can also come with time [how often do you actually use Python for GUI stuff, though...but still nice to have, just not its major use I doubt]
Another thing you'll miss from Python is accidentally typo'ing variable names and having to discover that only at runtime :)
Just my rebuttal :)