Just tried them today. These and the Bose Around ear headphones was what I focused on primarily. I have never heard Bose before and wanted to see how bad they are. If we stick to sound they are hugely underrated over here.
Comparison was on my Ipod touch 3G versus my Edition 8. I found both the Bose and the K530 to be very easy to listen to. Definiatly do the job to me when I don´t want to dig to deep into the music.
As for build quality well its below 100$ here so I think it´s good for it´s price point. Relatively thick cable and the construction seemed like it could take some beating. That its plasticky you have to expect at this price point. The Bose however had some ridiculous cable, they felt very poor built it felt you could break them just by handling them. And cost 250$? That they are overpriced I agree 150 % on but they sounded quite nice with a really nice soundstage. None of these got "destroyed" by the ED 8 but then I listened to it 10h a day the last 3 days so I needed the change perhaps
I loved the fact that the Bose headphones was smaller then the ED 8 yet fully circumaural and as mentioned they didn´t feel that claustrophobic anyway. My much bigger ED 8 doesn´t manage to become fully circumaural but it has much thicker leather earpads.
So yes the K530 did perform great. Much better then trying to run my K701 out of an ipod. More body to the music and doesn´t need as much help from clever amp matching to make them musical.
55 ohms they required slightly more juice then my ED 8 but no problem at all. How much they scale I can´t say of course. If they had the same casing as the Bose and didnt become sweaty so incredible fast I would probably have bought them. K530 was quite comfortable though the Bose take the price here even disregarding warm ears.
As for isolation it was really hard to tell here. The did manage to shut out the salesman that tried to except for selling the overpriced bose later suggesting the K518DJs over the K530? They did loose some of their mojo seeing the Ed 8 on my neck it seemed though
I didn´t even take a listen to the 518 after having the 81DJ torture instruments. Both the Bose and the K530 was warm but not excessively bassy at all on the Ipod anyway.