I do. The K712 sounds more natural to me. Specially with recordings of real instruments, which is most of my music. I like it's open treble, even if it forces me to back off the volume a bit, to make space for it. IMHO, the K712 has perfect bass presentation. Not anemic, but not bloated either. The 4XX has a bit better detail retrieval, it's also more even in the frequency response, so you can listen a bit louder, and hear everything going on in the mid range more, which is where most of the action is, without busting your ears with treble. But, drums feel less punchy with the 4XX. For electronically produced music, I recommend the 4XX. Just make sure you have a good amp for it. A weaker amp, like an O2, can get them loud, but they will be lazy, and will sound a bit veiled.