Both are trashy, however, to my ears, the HHX has the edge in the trashy quality that both cymbals possess.
What gives the HHX the edge is the weithg of the cymbal, the bell size, which gives it a little more sustain and wobble. The (larger) holes diffuses the air, giving it more trash qualities than a regular crash cymbal. Oh yeah, the larger hammering combined with the smaller lathing also makes the tone more complex (initial tone being high, then simmers to a lower tone) than the A Custom EFX, which has the narrow lathing and smaller pneumatic hammering.
All in all, it just depends on what you like to hear - a bright trash or a dark trash. You can't lose with either one. If you're a baller, get them both. let us know how it turns out for you.
