The Saitek panels feature pre-labeled switches where those labels can not be changed. It is possible to alter the function of the switch using tools like the XSaitekPanels plugin or SPAD.Next. Some of the Saitek panels have rotary encoders that can be used to adjust radio and autopilot functions. I found the Multi-Panel to be the most frustrating as it only has one rotary encoder to adjust multiple autopilot inputs. The input to be adjusted must be selected with a rotary switch that is not back-lit. It is IMHO a bit clunky to work with.
X-KeyPad takes a different approach by allowing you to enter numeric data via a keypad. Any simulator function that is backed by a writable dataref can be set with this technique. You also can get an optional verbal confirmation of what was set and to what value. The key layout is totally configurable with your own legends and you have a high degree of dynamic control over the back-lighting of each key.
You can control a lot more aircraft functions with a single XK-80 than you can with a full set of Saitek panels. The cost per function is much lower with X-KeyPad and an X-Key device then a full set of Saitek panels.
