Why Logitech the keypad above the cursor keys now horizontally instead of vertically aligned, unlike any I know predecessor sets, is puzzling. If you work on multiple computers, which are equipped with different sets, this means that you regularly caught the wrong button. If the process is, however, only with a keyboard layout, you will have it certainly accustomed quickly.
What I really notice when negative MK520 is the mouse. It is slightly smaller and lighter fall than the predecessor. In addition, the sliding surfaces has been reduced to the bottom in size, so that the mouse has a slightly wobbly. But that would still get over. Logitech has however saved the forward and backward function the scroll wheel. There are no keys for it. If you want the browser or other programs navigate, you have the mouse cursor become like in the Stone Age lead on the back button and click there. If you get used to the convenience of a corresponding mouse function, there are only two possibilities: Either refrain from MK520 or buy an extra mouse with an equivalent function in addition. Thanks Unifying receiver is likely to be the problem without other recipients. This was probably the intention of Logitech, as they decided to save this function.
My impression in brief: keyboard top, mouse flop!
