I've been playing GS 95 (listed as ultra light) shafts in a set of MP-56/63's I picked up used. Definitely have my share of thin and toe hits. The other day I tried an MP-54 with a KBS Tour S shaft, and although my club head speed was down by a few mph, I gained about 7-10 yards consistently. For reference my 6i swing speed with the GS 95's is about 85-88, and with the KBS' about 80-83
Is there an correlation between playing super light shafts and missing the middle of the club face? Shots definitely felt more flush with the heavier shaft.