* Java I2P has built-in applications for torrents, e-mail and so on. i2pd is just a router which you can use with other software through I2CP interface.
* i2pd does not require Java. It's written in C++.
* i2pd consumes less memory and CPU.
* i2pd can be compiled everywhere gcc or clang presented (including Raspberry and routers).
* i2pd has some major optimizations for faster cryptography which leads to less consumption of processor time and energy.
Use any open source browser - for example, Firefox or a Chromium based alternative. Create separate profile for I2P ([firefox instructions](https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles)),
and try not to mix clearnet browsing with I2P. Learn how to configure your browser for better privacy and security.
Floodfill mode make your router a floodfill, that means what other routers will publish and get LeaseSets and RIs on your router. [Read more](http://geti2p.net/en/docs/how/network-database).
Floodfill mode require more bandwith, CPU time. If you sure, what you have stable uptime, you can enable floodfill: `floodfill = true`