It's not just the interface{} thing that's annoying. From my point of view, Go has way to many annoyances to be decent. No constness. No protection against copying. No compiler warnings. Crap error handling. Public/private denoted by uppercase/lowercase letter (WTF?). Implementation details leaking into the language - such as the "typed nil" nonsense. Struct and interface embedding is insane. Multiple returns from functions but no tuples. Needlessly complex `for` syntax, needlessly complex receiver syntax. Needless magic channel operators (they could've easily just been functions).

The tooling is also annoying with the most glaring deficiency being the lack of package versioning, which I believe is going to change (or it has already? I don't remember). And then there are tools like `go vet` which basically just attempt to make up for the compiler deficiencies in sub-par ways...

Go has a very nice runtime, but the language itself and the tooling feels extremely half-baked. I'm curious whether Go 2 will improve upon this.