I had to go to the MAS props for my smaller planes.  I fly over grass, and I soon found out (as in on the first day) that the APC props break when I land in the grass.  I broke three props in four landings.  So, now I use the MAS props and haven't had one break since.  They're not as efficient as the APC props, and I lose thrust and run time, but it's definitely much cheaper for me.  More than worth the trade-off.

Mark