Went from a Woods .630" to a Zippers .567". The cams have almost identical timing though, so its no big surprise the powerband is simular. Low-end feels a little softer, probably due to less compression. I think the heads are flowing a touch better but didnt have time to test them.
On late model sportsters torque your pinion nut to 70ft/lbs and use green loctite. I think this is what caused my problems, because stock tq spec is 35-40 ft/lbs. This allowed the pinion gear to spin on the shaft.