It's too bad the Sextett actually sounds worse than the K240 Studio. The K501 is OK, but the Q701 is far better and doesn't have the massive soundstage of the K501.
I got rid of the K501 (and kept the K601) when I bought the Q701.
Have you seen the frequency graph of the K501? It's hilarious! Luckily it sounds better than the graph makes it appear (it's on Goldenears) or the Internet archive of Headroom.