Game's a blast at first, until you get all the mechanics and experience some better ships. The whole things is a grind, and after you notice that, it sucks, as there's no real depth to it. I got 250 hours out of it, though you can extend playtime by a lot if you're into the community, clans, PvP and all that. I got bored after maybe the 100th hour of playing alone, but it varies wildly on a person-to-person basis.
PvP is fun but extremely flawed, because the game works in instances, so there might be 2 groups wanting to fight each other that won't even be able to get in the same instance, won't even be able to see each other.
And I suggest you get a HOTAS setup, or at least a joystick. Game is totally playable with keyboard+mouse, and that's what I used for the first 50 hours, but the feeling of flying with a joystick is awesome. You should also at least try playing with a voice command thingy(I used VoiceAttack, which isn't free, but I think there are some newer alternatives) and some kind of head tracking. If you don't mind sticking a phone to the top of your headset, there's a pretty easy way to set it up.
I'm pretty sure this last "expansion", Powerplay, added some more depth and interaction between the players(as you can choose sides and do things for your faction), but it wasn't enough from what I read in the game's subreddit.
Oh, and they were supposed to release true expansions, as in flying down into the planets, walking around in stations and ships and first person shooting stuff, but... as much as I'd like to see all that, and see Frontier prove me wrong, it's probably never gonna happen.
I play this game simply for the exploration part of it. Flying to distant stars and seeing what strange worlds are out there in the Void? My ultimate science fiction fantasy.