I used this string with X-1 Biphase crosses. I'm not a string breaker but I wanted to try it out, and it did last me quite a while before it got that board-like feel (maybe 15-20 hours). It works really well on kick serves and I found it easier to hit angled shots in, even some shots I have no business hitting. I don't think I am going to continue using this string because I think a full bed of Tecnifibre Black Code (also pentagonally shaped) has more response/touch/feel and tension maintenance. Also, if you string your own racquets, this string kinks pretty easily and is not fun to use while stringing your racquet.