Other benefits to Sol system not yet mentioned:
- There's a 10% discount on Eagles at Galileo Station, the one orbiting Earth's Moon. Woo. Hoo. By the time you're ranked up enough to earn the Sol permit, you're usually way past wanting to fly an Eagle. But it's there.
- All five factions in Sol are Federation democracies. This means that every mission you do there earns you Federation rep. Become Allied with all five factions and the missions can really stack up nicely, especially with four space stations within a few seconds of flight from each other (the three orbiting Earth and the Moon one).
- Besides the view of Earth, there's also the view of Mars, which of course has been terraformed and is actually the designated Federation capital planet. Mars is a unique-looking planet because FD have used the actual real-life topographical data of Mars to generate it. I believe Earth and Mars are the only two non-procedurally-generated Earth-like worlds in the game.
- The new commodities introduced with the Engineers update has meant some extra-juicy new trade routes into Sol. As Earth is an extremely high population planet with a Service economy usually in a persistent Boom state, certain trade goods are in very high demand there. "Medical Diagnostic Equipment", produced by High-tech and demanded only by Service economies, can be very profitable (3000-4000cr/ton) but as word of this is getting out, the High-techs near Sol are usually sold out. As a Service economy, Earth is also prone to Outbreaks (since Outbreaks, bizarrely, are generated by successfully completing Biowaste shipping missions and Biowaste is the only mission shipped out from Earth) so shipping Basic Medicines to Sol is also often quite lucrative (2000-3000 cr/ton during an outbreak). For the return leg of a trade route, you can either deadhead out empty, fill up with biowaste, or fly to one of the Refinery stations (eg the Moon) to pick up metals.