Like the previous releases from Egosoft, it started a little rocky but to their credit they're really pushing hard on getting X4: Foundations into a good state.
Just recently they put out update 2.50 which includes: an entirely new class of resupply ships; a setting to blacklist ships from entering certain areas; improved inventory management with lockboxes in space and inventory storage at your HQ; they added a note/hint while mouse direct steering mode is active; more variations for Build Station, Rescue Ship and Scan missions and plenty more.
They also improved cockpit glass transparency, improved behaviour of ships docking at busy locations, the satellite deployment tutorial was improved, performance of saving and loading is also better, better gamepad support in certain places, AI improvements and so on. The list of bugs fixed with this release is quite long too, impressively so.
It seems like the Linux version is no longer in beta too! In the release notes they stated "Also with this release, the Linux version of the game is now available to all players" so if you've been holding off now is your time to jump in.