A diagnostic indicator is whether you gravitate towards things like Martini or Gin, which aren't idiomatic Go and seem designed to ease the pain of using Go for those who don't actually care for it much.
I have enjoyed the gin API. In maybe 10 lines of code, I can build a fast HTTP service that can serve up a small single-page app. The same thing using e.g. Negroni feels like I'm writing more boilerplate for no apparent gain – and I'm a great opponent of writing boilerplate code.
I love martini (and lately gin) and definitely love and use go every day. What about these frameworks is not idiomatic go?
Is there another framework that is? Or you suggest just rolling your own using net/http by itself?
Cheers
tl;dr - Martini doesn't have a strict, type-safe API. Overuse of reflection leads to a small performance loss but a much larger, much more important cognitive tax.
"Slow" in the case of a router/mux is entirely relative though. There's been this strange focus on routing speed/allocations, when its the smallest slice of your total request-to-response performance. Martini's router won't make your application noticeably slower than any other.