Right now I am listening to Van Morrison's "Astral Weeks" on my new K501 and it is just amazing. Dare I say it is a more human experience than my k701 or HD650. I am really thrilled with this headphone's ability to sound "genuine".
My personal opinion is NO. I have heard HD800 and have to say that although they have better resolution and bass extension they are not in another league when it comes to naturalness. I also listen to a great deal of classical music and jazz and k501 is a pure joy. I think I will buy another pair just in case something happens to the pair I own right now,