For context, I write
Glide.
GB isn't just about dealing with dependencies but a separate build tool that frees you from the GOPATH.
First, I really like the idea of being free from the GOPATH. The GOPATH is the #1 WTF element I need to teach new Go developers. It's a problem.
If you look at early versions of Glide we tried to break free from the GOPATH but found there are just too many things that break due to the internals of how the go toolchain is written. When vendor/ directories came along we switched because it offered the closest thing we could get.
So, I'm supportive of tools and changes allowing to break free from the GOPATH.
Second, If GB supported version ranges, resolution, and typical metadata I would start doing backflips of joy. It's some of the package management features I want that I miss there. I have dreams of making Glide compatible with GB but I don't have the time anytime soon.
Third, because GB isn't maintained or developed with the same level of effort as the go toolchain I can't ask the people around me to switch. If it was I would suggest more companies and projects use it. So, if you're interested in that kind of problem please help Dave out. Really.
I'm positive on GB. I hope it becomes a viable solution for more people (due to all the reasons that enterprises hold back from things like that).