Definitely a developer's tool.
This is a time-saving plugin. Need to whip up a custom post type, add a bunch of fields with repeating fields add a taxonomy and more? It's a great tool for banging out some quick results.
The UI is simple, slick and convenient in most ways.
I'd say that this plugin is aimed at the intermediate and up developer. It may be a good conceptual learning tool for novices. If you're looking to create custom post types, taxonomies, etc, you might likely be beyond the novice range anyway.
I do wish that it had more in terms of documentation, and specifically code usage examples for the new pages that one creates, and that the feedback forums worked though.
That being said, I recommend it.