agd/dphie/gamma phi

Who cares what guys/girls think? Based on your reference to what you “don’t hear” on campus, you are apparently a student and obviously not in GL.
If you truly want to know about each of these chapters, consider attending rush in the spring. Get to know these girls (and other chapters) they probably are in your classes and wearing letters. AGD might (not sure) have informal fall rush (believe they did last year). Gamma Phi and DPhiE maybe not because they met quota, but you can contact FASA to see who is having fall informal rush.
All chapters are always looking for quality women, so if you are truly interested in what these chapters are all about, then rush!
To answer your question....I think these chapters are integral, valued, and important members of Greek Life.

Get out and meet them. All 3 have strong sisterhoods but different personalities. GPhi and Dphie like to go out and party whereas AGD isn't quite as social but that doesn't make them bad.