Got another few days of listening in with the K52 and still really happy with the sound. They are sounding more relaxed and less metallic in the treble. The midbass is nice and punchy when called for and the overall sound is clean and even. Some of the shortfalls I notice are the cheap pad material which just looks/feels cheap and tends to make my ears a little sweaty after an hour or so of being on my head. I also wish the headphones provided better isolation from the outside. I might open up the headphones later and see if there is room to add some damping material to try and block out more outside sound. All in all these are awesome headphones from AKG and I look forward to more serious comparisons with them and my K400 and K240DF.