It seems as though the keys are slightly smaller than those on the K680, which is really advantageous because it allows the user's wrists to remain fixed while operating the keyboard, whereas this causes slight movement with the 680. In spite of what it may seem, the wrists did not move at all for the first half an hour of the activity. Aside from that, it has the sense of a complete analogue since it lacks us-block. summary: Everyone who types a lot yet hates hitting the keys should give it a try, as it is highly recommended by me. The fact that hands do not become fatigued by the end of the working day completely supports the relatively delicate nature of the membrane. I wasn't anticipating the presence of Cyrillic, thus I wasn't prepared for it. Delivered four days ahead of schedule, with a reminder call made the day before delivery.