Hi welcome to the forum. I had an S, now have a Y. Probably will get a second Tesla next year, and I initially thought I'd get an X for the room (I like the 6 seat version for 2 adult couples plus two grandkids). However, after no longer having my S, I really miss it. I love the Y, but it is an SUV type vehicle, as is the X. The S is more like what I had driven for years (BMW 7 series mostly). So, I think you'll miss the feel of the S, and whether you like the X or not will depend on how it feels to you when you drive it. I'm still not decided what I'll do either, but I have driven an X. It was more like the S than the Y is, in that it was smooth and substantial feeling. However, it was more floaty given it's height and suspension. The one I drove was before the new X suspension, so that might actually make a big difference. I'd drive a new X around some to see what you think.
Good luck!
Mark