As a mono guy in a poly relationship I used to think there were specific benefits to having a poly partner. Things like more freedom to do hobbies or spend time on your own while your partner is away with another Love.
I don't believe that any more. That has nothing to do with whether your partner is poly or not. It has everything to do with your partners independence. I don't feel poly partners are any more independant than mono one's in general.
In my case, I think the primary benefit of having a poly partner is knowing that there is some one else as committed to her as I am who will be there to support her with the same level of depth as I am. I guess that is why I see absolutely no benefit to having a partner who has casual releationships on the side.
Playing the Game of Life with Monopoly rules.
Monogamy might just be in my genes
Poly Events All Over