I've got a set of the crossfades and I have to say I agree with everything joker wrote in his fashion vs function review. In short, the cans are readily available on ebay at 100 new, and that is a very reasonable price point for them. At retail price of 200-250, you can do substantially better.
Assuming the 100 dollar price point, the crossfades put out powerful bass heavy sound that is comparable with the high end beats. There honestly aren't many options in this range that can compete, the primary option being the AT M50's. The M50's are a little lighter on bass, and way less attractive. The durability on them is top notch, and the various auxiliary features are worth considering. You get what I would argue is the nicest headphone case on the entire market, as well as removable cables (which is a huge plus in my opinion). With fashion being a consideration, the crossfades are a steal at 100. The AT M50's will offer a more balanced (and to most people's ears better for it) sound signature. The crossfades bring skull shattering bass, with nice features and gorgeous cosmetics.
Assuming the MSRP price point of 250, you'd be hard pressed to find a headphone that performs worse. Primary competitors here amount to the ms400, the denon d2000, various beyerdynamic offerings, grado 325's and similar, and the sennheiser 500 series.
The ms400 is the most comparable, offering a similarly bass heavy sound signature, but much more articulated mids and highs. They sport a comparable yet very different cyberpunk style, and really offer an upgrade in every metric i can imagine beyond the disconectable cable.
The D2000 is NOT a portable, but absolutely destroys the crossfade in sound quality. Much more articulated bass, and excellent separation between the various sound ranges.
The Grado and sennheisers are very different in that they are open backed, and bring a much more open sound. They are not really an appropriate comparison, as they fall into a different archetype.
The beyers I have no experience with.
TL;DR - go read jokers review. He does a very good comparison that includes the v-modas.