I think there is a large element of "look at me, ma!" on open mike, and I'm including myself. I always post up what I consider finished product, and I judge my success by the number of reviews I get. If I want peer to peer reviews on a work in progress, I go over to TAXI and their peer to peer board, which is very active (you don't have to be a member to participate). I am very active on open mike, in that I comment on a lot of songs. If I don't care for a tune, I don't comment at all. My pet peeve over there is people who post up their music -- some of them very long term members -- who never EVER comment on other people's work. Just like in the real world, as opposed to this cyber one, I notice people who only want to be listened to, and eventually ignore them. Why should I pay any attention to you if you can't take the time to pay attention to me?
On another topic, I want to say I enjoyed my time on JPF. Met a bunch of real nice people there.. I actually met Marc on that site, and he invited me to SongRamp. That was shortly after I called the owner of the JPF "arrogant" in a public post, and he decided I needed a "vacation" from "his" site. So he threw me off the site. At least he was paying attention to me . . . 
Ott