I totally agree with Raven. It is great for source for relationship advice. Lots of good info about communication and I also felt it really helped me to understand more about myself and what I want in my relationship/s in general.
For me (to answer your "why be with anyone else question"), even though I have a great relationship with my husband and we have fantastic sex, a big part of how I relate with people is emotional and sexual and a monogamous relationship limits my ability to connect with the people I care about. I have the capacity to 'control myself' and not cheat but an ethical and loving open relationship seems ideal to me. My partner and I are still in the first boundary defining stages, so most of this is all in theory, lol.
What other questions are you pondering?
(And yes, Feist rocks!