As an author of a program that will export metrics to Prometheus, my (perhaps naïve, but certainly first) expectation is to

```go
import "github.com/prometheus/something"
```

and then to refer to all of my Prometheus interaction through a single `prometheus` package, i.e. something like

```go
prometheus.Register("my-application-specific-metric", ...)
m := prometheus.NewDefaultMux() // autopopulates some metrics into prometheus.Registry
m.HandleFunc("/action", myHandler)
http.ListenAndServe(":8080", m)
```

From where I sit, having to import two things (or 1+N things, where N is the number of default helper thingies I want to use) is a distinction without a difference.