Like: The package and build system is amazing and just works. Simple, yet intuitive and powerful with the introduction of modules. It's hard to quantify the number of hours I've saved over other tools hunting down build/linker/dependency management issues.
Dislike: Error handling feels extremely verbose. I like the design choice to return errors explicitly, but it feels like there needs to be a return-if-error syntactic sugar introduced to avoid the endless if err != nil ... return err peppered everywhere.