Here's an interesting discussion on leading edge radius by Don Stackhouse:

http://www.djaerotech.com/dj_askjd/d...lunt_wing.html

Don mentions that sharper leading edges produce a gentler stall, but does not quantify the accompanying reduction of maximum lift, or the effect of a gentle stall on aerobatic performance. A sharp stall break tends to promote cleaner snap roll entry and recovery, I think.