The CT250 Flight Control Driver was a great driver. I continued to play it until last year when I finally changed the KE4 TC Driver. Since the USGA limitations have not changed on driver performance since the CT250 came out, and the fact that we design the performance to be conforming and right up to the limit on the ball speed element, you do not loose ball speed performance by playing with the older driver. That being said, you do gain adjustability with a driver like the KE4 TC. If the driver is fit to you (loft, shaft weight and flex, length) and you are comparing apples to apples, the technology in the face and how we measure ball speed performance, there would be little difference. However, variations in the cg location could effect the spin and that can make one of the drivers perform better than the other. I suspect, despite what other manufacturers will say, this would be true for most drivers made in the last decade +. If every new model year we all gained as much distance as some of the manufacturers say if we try the “new” driver, we would all be hitting it 500 yards. The fact is, the USGA has dictated how fast the ball can come off the face for a long time and all manufacturers that design and sell conforming drivers stay within the parameters set forth by the USGA and technology has allowed us to design right up the limit, and still stay conforming. We know (or have a strong feeling) a change is coming from the USGA and the tolerance limit is going to be reduced on the ball speed number. I do not believe it will have a noticeable effect for most players, but if they combine this with new golf ball parameters and driver playing length parameters, you may see some reduction in distance. I guess that is another discussion altogether.