My personal experience with the third party Prosper forum was good, at the beginning, but by the time a large number of sockpuppets (and people without any money invested, who stuck around to comment about everything) showed up, it became a lot less fun.
Alot of forum users seem to have arrived from a forum called CreditBoards (which is a discussion board that seems to be devoted to people helping other users get away with stealing money from their creditors). Some of that was to be expected, I guess, but these people seemed to be online all the time and never had anything positive to contribute to any discussion, and didn't miss any opportunity to badmouth Prosper.
That, plus the constant whining and negativity from a bunch of the older Prosper forum users about stuff that did not even have to do with money (which is why I signed up and why the handful of other forum users who I had fun talking to about financial stuff, aside from just peer to peer lending, also signed in to the forum) is what killed the forum for me -- no utility in reading stories from a bunch of crazy people who air personal dirty laundry on the internet, and treat the forum as though it's a support group -- rather than talk about making money.
In the end, I guess it's like Warren Buffett says: Those who will not fill your pockets will fill your ears.
I'm still really interested in p2p lending, as an investment, and I still talk to a few people about investment strategies and stuff, but I feel like I should have known better than to do anything like that in a public discussion board forum. Those of you who know me know how to contact me.
Back in 2006, before so many people arrived with so much "personal baggage", we had some good conversations on the original Prosper forum and on Prosper's official forums, too. But ever since the number of forum users grew beyond about 500 or so, and it got moved over to .org, things got weird and political and too who-likes-who for my tastes, and the whole board just went downhill, pretty quick.
Fun while it lasted. Thanks to those of you who taught me some things and had some good discussions.