I shot "fat" carbon shafts for a few years, in fact the last time I won the world I was shooting CE CXL 150's..but as a 3D shafts their a double edged sword. Shooting in groups with average shooters, I felt fat line cutters were good for 4-6 pts on a 40 target 3D course....however when shooting with above average shooters, who most times stayed in the 10 or 11 ring, you lost 4-6 pts per 40, with glance outs from crowded scoring rings and oversized shafts.