http://immortal.i2p/nested-posts/36
On i2p, outproxies (i2p exit nodes) are optional, so you can choose to stay only on i2p network, completly isolated from the clearnet. On i2p, every client is also a router, and that helps the network, where on tor you have to set up a relay to contribute to the network. In terms of content, i2p is less used than tor, so you won't find as much hidden services here, but not more or less bad things, just less things in general.