A couple of things could be said for Goldberg. Based on your original
description of your needs, it might be a very good fit. Goldberg
gives you a simple CMS where you can create content pages and put them
into your site's menu. It also allows you to add your own Rails apps
and add their actions to the menu too.
There's an almost-zero learning curve with Goldberg: you code your
apps as normal using Rails and just drop them in. You don't have to
learn any custom tagging systems or anything. Configuring your apps
so they're secure and putting their actions in the menu is done
through the web interface.
As linoj noted, you can back out of Goldberg later if you decide it
doesn't suit you.
A fresh install of Goldberg bootstraps with some sample data and
layouts, so it only takes a few minutes to set it up and give it a go.
But the #1 argument (I think) for Goldberg is that it offers one of
the most powerful and flexible security systems of any Rails
framework. For controller security, it has a role-based security
system that's integrated with navigation: users can only see actions
in the menu to which they have permissions. And you can use
information about the currently logged-in user and their credentials
to implement model and view security.
If you want a blog or something then sure, there are lots of better
alternatives out there. But if you want to deploy an enterprise
application on the web using Rails, I think (and I'm completely biased
of course) Goldberg is the premier choice.