This is an interesting question, but purely subjective. You could just as well poll users "were you disappointed that the store was out of chocolate ice cream, but might have more tomorrow". If you went to the store for chocolate today, then you may be disappointed. If you wanted strawberry and they had strawberry, then you're probably not disappointed.
Personally: I went from a 7+ to a X.
There are some features I miss from the 7+: landscape mode for the home screen and settings, no notch & rounded corners eating up parts of full screen videos, swipe up for control center, etc.
There are some aggravation of the 7+ I do not miss: the phone doesn't poke me in the hip when I bend over to tie my shoes, I can type easily with 1 hand without sliding the keyboard to one side, etc.
There many things I really like about the X: the hardware is very fast, FaceID is surprisingly accurate and fast, the overall form factor is easier to use one handed, swiping up for the home screen actually feels pretty good and natural, and all of the typical yearly improvements (camera, memory, etc).
There are things I dislike about the X but they're almost all software and could change: swiping down for control center from the right corner, I'd like the option for FaceID to unlock to the home screen without swiping up, reachability can be hit/miss, FaceID does not work with my sunglasses.
Would I want an X Plus? No. I think it would provide most of the benefits of the X, a small number of the benefits of the 7+, and a LOT of the aggravations I had about the 7+. But that's just my answer and I'm not disappointed because I like strawberry.