I called predator to ask the difference between the sport 2 butt and the bk 3 butt and was told the "construction is very similar". They couldn't really tell me more about it outside of that. I was thinking to keep a set at work that I can easily carry around, so I was considering on getting a bk3 with a sport grip and a z2 shaft to play with on it. Has anyone tried this? Or anyone who has access (dealer) give it a shot? I was thinking this would allow me to have a break and play cue with just carrying 2x1 in a cue bag.