Ja, ich auch! (Anyone want to help me with my German?)
I'm totally with you. The soundstage comfort, and clear mid-range make these fantastic for gaming.
I purchased the Fidelio X2 to replace the K7XX, and after seven weeks, I'm finally ok with moving on from the AKGs.
The K7XX is great for gaming, but I'm a relatively new audiophile, and need to try out more gear so I have a better frame of reference. I should probably grab an HD650, since I like a warmer can, and some have favorably compared the X2 to this classic.
Since the K7XX is a product now, there will always be one out in the wild (or in the classifieds), should I change my mind and want to buy it again.
If that happens, I'll be sure to tell everyone here I made a mistake.
The HD-650 is a great sounding headphone but you will need to look into the rest of your chain if you want to get the most out of it. The K7XX is easier to drive than the HD-650 and the X2 is even easier, the best results I've had are with a BH Crack, second choice would be a Project Ember. The Ember also works quite well with the K7XX while the BH Crack not so much. For gaming the K7XX is better but I've come to like the HD-700 even more for gaming, and also watching movies.