I've seen some pics of roger federer's string savers and the look pretty neat. I was thinking about probably getting some but I have a few questions 1. Do they fall out easily 2. are you allowed to play matches with them on? 3. Does it affect the playability of my racquet/strings in anyway? 4. How great do they increase the life of my strings(Wilson Champion Choice)? 5. And finally, for a string breaker like me, are they worth it?