I like the idea of replacing the builder selection with defaulting to a public URL then an internal one if public is not available. We'd have to figure out what to do about linking to Milo though. 

Was there a reason why people wanted links to uberchromegw on builders that were public in some instances? I feel like I have a vague memory of something like this, but I'm not sure. 

If we can come up with a good default behavior that people like, I think it's better for users to not have to think about too many settings. 

uberchromegw offers extra features like canceling/retrying builds, comments on steps etc. The radio button is to support sheriffs who want to use these features.

It is probably better to link to public by default but uberchromegw for now, if we know it's an internal builder. Eventually Milo should probably implement the extra uberchromegw features and we can delegate the ACLing to it once we link to it for all builds.