Played it for 3 hours when I first booted it up.
Got a new computer the same week as launch, which hopefully will be able to run everything maxed for the next year. I get some stutters that people mention, but mainly tied to ship and some slowdowns at random. Other than that, fairly smooth. Considering the graphics though, it should run at 200+ fps.
I enjoy it, but it can definitely be more, and with the cost of admission, it should be. If they release a DLC that adds building on planets, creating ships and actual multiplayer, it should be free. This game cost more than the Witcher 3 at launch. The next Deus Ex game is also cheaper than this on PC. I can't imagine the cost of those productions were lower than this.
Simply put. It is too expensive now, but with a sale after more features get patched/dlced in, it could be a steal.
I'd advice anyone who hasn't bought it yet to wait, and if I had not played it past the 2 hour mark on Steam, I'd refund it now and get it later. Note first 30+ minutes were spent altering settings since every change requires a reload of the game.
PS: To new players. When you first load up, if you don't like the look of your first planet, closing the game will put you on a new planet. The first one I started on looked like a tropical paradise, but after 2 reloads for settings, the planet I ended up playing on was a barren wasteland with toxic rain. So if you like your first one and want to alter settings, remember to save before exiting.