I am one of those fortunate people who breaks strings. While I hit with alot of spin, usually I break string returning my opponents hard first serves.
I went string crazy for a long time trying just about every premium string made. The challenge for me was that I also have a sensitive elbow. This made chosing a string even more difficult as the tougher the string, typically the tougher on the arm.
I found a few multi-filaments that played extremely well and were easy on the arm, but they just did not last. I found most polys played poorly or hurt my elbow.
I finally found a poly that played well called big banger ace by luxillon. The problem with that string is that it's 18 guage and it broke alot. So, at risk to my elbow, I decided to try luxillons alu power 16l. My arm did not like it at first because I did not follow luxillons instructions to reduce the tension 10%. Once I reduced the tension to an amazingly low 51 pounds, I found It not longer bothered my arm and amazingly still played very good.
I played happily with alu powers for about a year. Then, one day, I was talking to a pro who convinced me to try Pacific's X-force poly. It is an orange colored string that he claimed was very similar to the luxillons but for less money. I am happy to report that this string is everybit as good as the luxillon with maybe a bit more power.
I would definately buy the X-force strings again but I suspect there may be a better deal. I suspect that these X-force strings are nothing more than a re-package job on a german string called signum pro that I read about on stringnet forum. My logic for this suspicion starts with their color and comparative to construction and performance. I hope that this suspoicion turns out to be true because the signmum strings can be purchased at a very low price. I am going to purchase them and see how they perform. If it turns out to be the same good string, I will update the other string breakers out there.