not worth the trouble?
I have been a member of a few private trackers. normally the only ones worth the trouble are highly nich'e ones like the now sunk undergroundgamer tracker (them and blackcats) are for retro games. sure there is the issue of of higher anonymity, but anyone that thinks a private tracking is protecting them from troggs is mistaken.
and normally for most content (there are acceptions) if you can't find it on tpb or kat.ph it can't be found.. although you'll see more 0day content on private trackers but it trickles down into the public trackers fairly quickly.