I still have some time but I am pretty convinced I will be staying with the 8 Plus. Now that said, I am 6'8" tall so my hands are pretty large. I can one-hand the plus when I imagine majority cannot. In the end, the width of the 8 plus and much of the video I watch being 16:9 are the deciding factors. But I agree with you, the X is definitely the more exciting phone. The smaller size is great, the gestures are so smooth, and the screen is beautifully bright yet maintaining gorgeous deep blacks. The aspect ratio is the ONLY thing that holds me back, but it happens to be a big thing for me personally.
Loving tech so much, particularly iPhones, I am saddened that for the next 12 months I will likely only be reading about the X. While I feel the 8 Plus is a very polished refinement of the dying design, I know that it is now forgotten. From here on out, articles are going to be X oriented and that bums me out lol.