I will not repeat everything that others have already written before me, but a point has been mentioned in any review:
For me it is important for keyboards that you can configure it so that the F-keys by default in the 'normal' mode run (F1-F12) and special functions (search, volume, etc) is activated via the Fn key. That can be activated both in K810 and in K480 by software. There are, however, a crucial difference between the two keyboards:
The keyboard is not managed as the K810 and 99% of all devices on the Logitech SetPoint software but on the new Options software. That compared to K810 both advantages and disadvantages. Firstly, the option software is significantly slimmer than SetPoint (which draws on every update again 78MB from the network). Until the last version of SetPoint, there were also massive problems that Bluetooth devices were not recognized, depending on the Bluetooth stack of the PC.
The crucial difference, however, that the option to the F-keys in SetPoint (K810) is set globally and applies to all three paired devices. In Options (K480) to each setting applies only for this unit. This can be advantageous if, for example, you want to have the option is active only for the work PC, but not for the media center and also not for the Tablet. However, it can also be a disadvantage because Options must be therefore installed on all PCs on which the function is to be used. Who wants to use the keyboard, for example, at home for your own PC and work laptop (without admin rights), peeps into the tube and should therefore rather take the K810.