After using the AKG K-712 Pro for almost a year, I can't do anything but recommend them.
These headphones cover every genre of music from fast metal to sweet string orchestras and EDM. The detail, clarity and soundstage produced from these cans is incredible, and with a tiny emphasis to low-end I am satisfied and won't look back on the purchase. Response is incredible. Not that you have to tweak anything, but if you want, fiddling with equalizer is okay since the sound won't go muddy or harsh. I use these headphones for music, video editing, gaming and for playing my guitar. Whatever I do, it's a joy.
I would not take the headphones outdoors or for travels because of their size. Because these are power hungry, a headphone amplifier is a must. I have paired these with a Fiio e10k, and I feel like I need more power for higher volumes. For normal listening volumes Fiio does just fine. Comparing to Sony MDR-7506, the AKG K-712 is a lot more friendly to people with sensitive ears for higher frequencies.
First pair I received was faulty, and I returned them. Thomanns service is stellar, and the new pair I received hasn't shown any weaknesses on the build quality. As a last note, the memory foam pads provide incredible comfort.