Make sure to take note of the ACTUAL pre test tension, in addition to the intitial starting tension when you are looking at the TWU stiffness digits. Without factoring that in, the data is almost meaningless.
The stiffness test takes place after 20 good whacks with a test hammer, the impacts are simulation equivalent to twenty 120 mph serves. After those impacts, many of the TopSpin strings have lost 30 lbs or more from the initial 60 lbs... TopSpin CyberFlash 17L is at 27 lbs
at the time of testing. So it's no wonder that lots of these polys test as being soft. It's because they are leaders for tension loss as well.