I've worked with all three of these languages and also with Java developers converting to these languages and far and away Go is the easier one to convert to. With the improved cold-start times and the ease of conversion for a Java developer, it is a no-brainer for me.
The hardest part of the conversion though is going to be the lack of traditional Classes so you have to be mindful of that, but Go Structs and interfaces tend to make up for what is lost there.
Full Disclosure: I'm a 95% Go convert (from Python) at this point in time.