I work on a full size helo that has swept blade tips, or to give them their proper name BERP tips. Their job is very simply to reduce noise and increase fuel economy by reducing compressability on the advancing blade. Some more effects of BERP tips are reduced tip stall and a produce more stable vortex at the tip. Since all this significantly increases the flight envelope of the blade I would have thought this would affect the aerobatic performance of any helo full size or otherwise. The by product of all this on our EH101's is increased fuel economy and a quieter helo.

Dave