It's a love letter to Privateer, first and foremost (full of references to it and the Wing Commander games, as one would expect). I haven't finished the main storyline but roughly got to most of the top-of-the-line equipment in 18 hours of gameplay, and will now go for these missions. As for the gameplay itself, it's a good space shooter with an enjoyable trucker feeling, particularly with the radio (the soundtrack is one of the highlights of the game IMO) and works well for short sessions. As of now, though, it doesn't look like it rewards exploration the same way Freelancer did nor allows for the kind of persistant world-building the X series has: keep in mind that it's not a criticism, as the game was made by a small team and is much better than what we'd come to expect otherwise (usually, indies from such group sizes tend to be your run-of-the-mill Metroidvania pixel-art retro-shooter, etc., when RGO is an A/AA quality game, so kudos to the devs on pulling this).
Personally, I believe I will put the game aside once I've finished the storyline, as it's unlikely to have more to offer until the mod tools are released (in which case, depending on what they allow to add, I'll try to get a Wing Commander ship pack for the community here - and I do think they'll release tools allowing it, as it's probably one of their unofficial but very obvious goals).
Now, as for choosing between these? I'll buy Squadrons as well as RGO, and I believe Squadrons will have a more intense and memorable experience, if only because it's Star Wars, it has a much larger team and VR support, which are very strong arguments for a great space sim. I'd recommend, however, to buy RGO because it is a genuinely good game within its limits, and a work of love for the franchise we like. Mafia can wait a bit. :-P