I really like SP4, but tried Cyberflash based on similar reviews. I could not detect a difference. The Cyberflash played just like the SP4 to me. I compared the Cyberflash 1.20 mm (18 ga on the package - 17L on the TW site) to the SP4 1.18 mm (17L on the package). The Cyberflash costs less, so it might be a better value. The cross string is generic 18g Gosen synthetic gut. My comparison is limited to a fresh set, so perhaps durability will be different. I have not broken the SP4 -- I just cut it out when it is dead. I hit moderate topspin and play virtually all 4.5 doubles. OHB, predominantly topspin.