Honestly not at all. Just put them head to head with my HD650 with The Moody Blues - Lunch Break-Peak Hour [FLAC] and they held up fairly well, without any glaring distinctions in the pitch. Not saying it holds the same intensity, but these two are in completely different price ranges.
EDIT, forgot to mention I did not use my Clip Zip to test. Used Foobar2000 on my computer through a DAC/Amp
I wonder how these compare to dasetn/kingo or even pk1/blox . But i'm really interested in trying theme if they compare to hd650 . And for 5 bucks there isn't really any risk