Get the X5. Out of the box it’s ready to go. Add a Gray Guns trigger and talon grips and it’s even better. After that you can spend the rest of the time practicing and not worry about what you can do to make it even better.
I honestly think the fact their is no tinkering required after you put in a Gray Guns trigger, except playing with recoil springs, allowed me to dedicate most my time to dry fire/live fire vs going to the range to see if the new disconnecter or trigger spring worked.
Hope that helps.