Re: X is tough?
I think overall it's as tough as the original X, especially more durable for side impacts obviously. But the front glass should shatter more easily because it curves back and doesn't have the protrusion on top and bottom like the original X to raise it. Actually it does, the earpieace and speaker grills protrude higher than the glass surface of the phone, this will help prevent the glass cracking, but only in specific and lucky scenario, perfectly face down on a completely flat surface. Also it help the screen not scratch if you put the phone face down.
Even if you don't use a case, tempered glass screen protector is a must.