Don't get me wrong, swapping pads can be done succesfully, even between brands, but at some point, you are likey to mess up and end up with uneven pad build up, and have to turn them theroghly and start over.
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
Read the rest of their tech papers, and you will know everything there is to know about brakes...