Well, I have the K3003 and A4's and am still waiting for a detailed comparison of the A4's to A5's. I prefer the A4's to the K3003's. The signatures are quite similar, imho. However the K3003's can sound a little brash compared to the A4's. I am wowed more often by far with A4's than the K3003's. The A4's may be a little lighter on absolute detail, but it's close. Hope this helps in a sideways way at least! Really, I am not going for the A5's at present as I am worried that the A4's are actually more balanced sounding, especially with the talk of treble troubles.