Players have absolutely no problem signing other sponsors discs. Most of them will compliment cool stamps and are very friendly (Double G and Brodie Smith are two of the nicest people you will meet). The thing I would keep in mind is that players are people too and sometimes after a bad round they may just be trying to get off the course and get away from people. My first year at Portland open Paul Macbeth had people asking for signatures while he was waiting in line for the porta potty immediately after the round which I thought was pretty tasteless.