If you make REST APIs, then you can use a micro-framework because there will be less boilerplate to get to what you want. Goji and Gin offer great performances compared to Gorilla, Martini and the others.
I see a lot of companies using Rails or Django for their main app and Go for their background processes. I think this approach is a good first step to get better performances and knowledge of Go, keeping the productivity of these frameworks to render HTML apps.
My experience of building complex web stuff in Golang is very similar to my experience of doing the same with Sinatra: you inevitably realize about 1/3rd of the way in that you're really just building an underspecified, undertested version of Rails itself.
(Assuming you build those, and I'm not suggesting that it would--more looking for additional viewpoints.)