I find that I like I2p quite a bit, but I'm not as fond of the reference implementation. It's in Java, which makes running it on small systems more difficult, and it routes traffic by default.

Routing by default GREATLY improves the network, but may be undesirable/unrequested behavior by people.

For you I2P users, What are you using for P2P software, I2PSnark, iMule, or I2Phex? I tried it a few years ago, but didn't have much success in finding anything. Any tips for setting up, searching, performance tweaks?

Yeah. I want to host an i2p site on my AWS free tier account but can't because it will exceed the 15 GB bandwidth limit due to all the volunteer routing.

You can disable/lower routing. There is also bandwidth limiting. I don't recommend disabling the routing entirely, however.

"small systems"; I get that it can be hell-like on very small systems but the Raspberry Pi works great.

There's a thread on zzz.i2p about it.

If you're interested in running networking applications on small hardware, you may be interested in the Beaglebone. It's more expensive, but vastly outperforms the Pi with regards to network I/O. The Pi is awesome for video, however.

It's ENTIRELY possible that that I didn't tune it correctly, but when I was looking at it as a routing underlayer for Tavern.com, it didn't leave me a whole lot of resources for running my apps.