I know it has been discussed before, but I believe the only way to address all these issues is with the introduction of feedback threads opposed to Kudos thread.
If someone has a bad experience then why should they not let others on the board not know to save them from similar situations. I did not know that ones kudos thread could not be trusted when I went ahead with my last purchase. It's not so easy for the more casual boardies to stay up to date with these probation threads etc.
Sure people can abuse possible feedback threads but the same can be said for the Kudos thread, with mates posting bogus kudos messages. The feedback threads will have strict rules and obviously be moderated (however little moderation occurs, nonetheless).
That's my on the topic. It's probably been done to death but just shows there needs to be a change.