A straight upgrade in my opinion? Yes, but only if you're willing to shell out a ton of cash. I think the HE-6 and HE-1k are both better, but not in proportion to their cost. Beyond that, I haven't really found anything that I enjoy significantly more. The 500, at it's current price, does so much right. The HD-650 is a fine side grade. Both are fine headphones, but it really just comes down to personal listening preference on that one.