I have no problem keeping a pos ratio. I generally will seed 1:1 on the popular stuff, and the more hard to find stuff (old sci-fi audiobooks, etc.) I will keep seeding. It takes forever to get some of that stuff, simply because the demand isn't there.
I like Demonoid because there is a lot of stuff there that you can't find elsewhere. They do have outside torrents as well, but they will be marked with an (external). There is kind of a community feel to it. (If you want a code, lmk.)
Oh, I should add...no porn there.