I have the same problem - Just bought the R7 with the Speeder 757 S shaft and so far so good. I only have hit a couple buckets at the range but heading to Florida this weekend to give it a true break in. But from the few balls that I hit I noticed that the high right balloon balls were gone that I was getting with the Cobra 440SZ with the NV 65 S shaft. I was just going to replace the shaft in the Cobra but I decided to get the R7.