Features can only be as powerful as the components that they encapsulate, and solid exportability isn't always there. Content types are probably the most tricky problem since they are so tightly coupled with the actual site content. (Although field groups shouldn't be too hard.)
When you create demos like this one it's easy to just focus on what you can do. But you're right, in the real world there are issues you have to deal with, so thanks for pointing out some of them.