So I am 4.5/5.0 tennis player and have been using RPM blast 17 and Xcel 16 in a hybrid setup at 57/56 lbs respectively. My issue is that I will burn through the strings within a week and a half almost two weeks playing for three times a week for 1 1/2 hours to 3 hours depending on practice or how long my matches go. I tried a full setup of RPM at 52lbs and found that it felt like I was hitting with a lead pipe because it had a dead ball feel and killed my elbow. Some of my teammates have recommended I try Tecnifibre blackcode or their new line X-code. I know the best thing to do is to go out and buy packs of strings and try them out, but I am trying to create a small list of strings so I don't spend large amounts of money on strings. I have tried all the Luxilon strings and did not like any of them as well as kirschbaum, solinco and Signum Pro. Is there anyone currently using blackcode or X-code that can give me better insight about these strings before I start buying new packs of strings.