I have some Phiaton PS 500's, sent to me for review (disclosure - I get to keep them). Overall, I like them a lot, good bass, mids and highs, lots of detail, but nothing overwhelms. The sound is much more intimate than my A900s, which sound more airy, they're more like the Beats by Dr Dre but with a bit more detail.
I don't find the Phaiton's very comfortable though, they sit on your ears rather than around them, which i've never much enjoyed. If you don't mind that they'd be good headphones. Build quality seems average, they seem a little flimsy and plasticy.
Overall: very nice sound, shame about the comfort.
If you have questions ask away.
You can see my full (but brief) review
here.