I really like Rupert Gethin's analogy of language - the Abhidharma is like the grammar manual whereas the actual experience/practice of meditation is speaking the language. You can't really speak the language (unless of course you immerse yourself in the proper environment) without some study of the grammar. However, simply studying a grammar is, for most people, a rather boring task.
You're right that the Abhidharma cannot be dismissed. It is the basis for much of the terminology used in Yogacara and Madhyamika.
=Thank you for the links, Jhana.