I quite like it. You don't get too many good MTL devices nowadays I feel. The driptip feels similar to actual cigarettes, which I'm used to. Airflow control works well and stays at what I set it to. However, it is sometimes harder to see the setting in bad lighting conditions.
Overall I like the new UTECH coils - good flavour.
But keep in mind that I come from an eGo ONE and Delta 19 clearomizer which I feel is an unfair comparison.
Edit: I forgot: You can't change the drip tip on the X! Only the black plastic thing on the top. A bit of a disappointment to me, as I would have loved to stick a longer metal one on top.