The X1 has many good points and a few (you asked for opinions!) bad ones.
I found it did not meet my personal "comfort" zone for live performance. The fill-in and variations buttons are on the right (as opposed to left) side of the keyboard and necessitate either using the right hand to access them, or a clumsy reach with the left. If you are able to use footswitches for these functions, then it may not be a problem.
I had problems that were never resolved with certain voices, notably Distortion Guitar, and a couple of others using the same effects. They didn't work unless you turned OFF the effect, and of course that didn't sound as it should either.
The vocal harmonizer required a lot of trial and effort to get it to work right. It worked very well once you figured out the proper settings and saved them.
The owner's manual is very close to useless. There are additional learning tools available. I believe DanO made a video to help with this.
The drum sounds are tremendous. I didn't care for the pianos. Guitars are good, but I like the ones on PSR9000 better.
I didn't like the weight of the keys, but many consider this a positive. Personal preference.
There are no touch pads to add parts or sounds in real time. Seems like a small thing, but I really missed this feature when I had the X1.
Vocals sounded good through the X1, but processing dedicated to the mic, such as e.q., effects, etc. was limited.
These are a few of the areas that I remember bothering me. Good luck with your choice.