@tobias: I finished some tests today. ANet produces less overhead and also sending data causes much less trafic then GS Network. I will release an article about ANet vs. GS Network soon, to clear things up. The article will include all source codes and executeables so that you can try things out yourself.

If you don't own GS Pro, you won't be able to finish a MP game because really necessary features are only available for Pro users (like sessions, data encryption). That's why plugins were created. The plugins allow you to use multiplayer even if you don't own an GS edition that supports multiplayer.

Try out my ANet plugin. I think it's easy to understand for beginners and it comes with several tutorials/howtos/examples.