I have been a member of ARLIS/NA since 1988, and, even though art librarianship is just a part of my responsibilities as Arts and Humanities Reference Librarian, in my experience ARLIS/NA offers conferences with a wide variety of relevant sessions that are useful not just for art librarianship, but also for other parts of my job.
Discussions about the hidden Internet, information literacy, copyright, technological advancements, and digital resources are the same issues discussed at ACRL, but rather than ten sessions on a variation of a theme, the one or two sessions at ARLIS/NA on a topic tend to be of very high quality and very informative. Some of the specialized sessions at ARLIS/NA actually have content which does translate into other disciplines: for example, services for and strategies to help studio artists can be used as templates to address needs of other types of practicing artists, such as creative writers, dancers, and actors. The means of helping such populations are not addressed at other types of conferences.
In 2000, I was given the responsibility of purchasing the foreign language materials for literature - we don't purchase very much for art - and made contact with the vendors I use for French, Italian and German literatures at the annual conferences and was able to discuss with them what I wanted to accomplish with our literary collections.
The sessions at ARLIS/NA tend to be very balanced, so that I don't feel I'm hearing yet another session on information literacy but instead am seeing through this focus on a specific kind of librarianship a larger picture about the practices and theories and responsibilities of our profession. I continue to find the conferences I attend invaluable for my development as a librarian overall as well as my specific responsibilities for the art and art history department.