When i started playing pool seriously i bought a jacoby with a z2 off my buddy, played with it for about a year and a half, has very little deflection.. About 6 monthes ago i scored a predator 3k7 with a z shaft and used that right after i sold the jacoby/z2. In my opinion the z2 has less deflection with the smaller ferrule, hits much stiffer than the z. But in my honest opinion i liked the original z better, it gives you a little more feedback, and i only had to adjust a tiny bit from the z2. But at the same time i like the feel of the z2 as well. I had triangle tips on both and they were both 11.75 with steel joints, so the variables were very comparable... if i had the choice between the two, id probably flip a coin