I take it you use enums fairly regularly?

I don't really use them that much, so they're superfluous for the most part. Sort of like a car having a bowling alley. I mean, I'll take them if it doesn't complicate the language or impact compile time, but if they're doing to do either of those, I'd rather just leave them.

Adding default branches into the couple of switch statements and a couple spots for custom json parsing that return errors for values outside the set doesn't seem like a bad tradeoff.

It's not optimal but one can still implement enums in userland using struct and methods returning a comparable unexported type.

I think that's a bad analogy because I actually use ABS and TC. I don't really use an enum heavy style of programming. Maybe twice per project or so. Putting a default branch in a couple switch statements also seems to get me back the same safety (although I'd rather detect the error early and return it in a custom UnmarshalJSON method for the type).

I also imagine I'd use a bowling alley in my car ~2 times per year, tops. So that seems like a better analogy to me.

edit: I guess I should bring up that I don't use go's switch statement much either, and when I do, 99% of the time I'm using the naked switch as more of an analog to lisp's cond clause.