I've used Gin for several small to medium projects without too much difficulty. I think Gin is a good way to learn quickly since its ecosystem introduces you to a lot of the pieces you will need. Personally, I don't do enough web development to grow out of it, since my web related projects are not a primary focus.
One thing to note is that Gin's Context is not the standard context.Context, which some find problematic. Most (vocal?) Gophers prefer sticking with the standard library and Gorilla.
I didn't like Gin because they don't let you use whatever routes you want. Something like /:category/:product and /user/:name (notice no ":") is not admissible because ":category" in the first route clashes with "user" in the second route (wtf?)
One thing to note is that Gin's Context is not the standard context.Context, which some find problematic. Most (vocal?) Gophers prefer sticking with the standard library and Gorilla.