This blog post from a few years ago suggests that using BitTorrent services over Tor is a bad idea for multiple reasons. However, it also suggests some fixes to get over these problems.
Is using a
It doesn't make you anonymous. Torrent protocol wasn't designed with anonymity in mind and there are a million ways you're going to leak your actual IP address.
Tor is a TCP only network.
While this doesn't give you the anonymity you wanted, it will hurt the network for other users.
Depends. It's definitely smaller than TOR because people don't know of it. It's slower, but if you don't need things on demand, have a seedbox or some way to torrent 24/7, things are quite acceptable.