I can speak from experience here.
I purchased an S when, after nearly a year of trying, I couldn’t procure an X.
I was really blown away by the “little console that could”.
I finally stumbled upon an X the day after Black Friday and made the switch.
I can see definite improvements in the textures of the cockpits foremost. I fly the Carenado C170B the most and the OAT gauge face was pretty hard to read on the S, but looks great on the X.
The added draw distance is also a very visible and obvious improvement. This is most obvious whilst taxiing.
Beyond that, there are subtle differences, but the S is no slouch and a remarkable powerhouse for its price point and availability.