Very little to be worried about using a carbon fiber props. They are almost used exclusively in IMAC - Home of Scale Aerobatics. Better performance, quite, long service life, etc. Most any prop will shatter if it hits an object. BTW - durability of a prop should not be based on how many nicks it can sustain from debris, tree limbs etc. This should always be avoided. You nick it = replace (any prop)
Above prop used for over 6 years of IMAC competition on a 43% Extra. It was in front of a 4 cyl. 20+ hp gas engine. Some of these are even hollow inside. Xoar (who makes some of the I2 props) is well known in the RC community. Also - Carbon fiber props gaining exceptance in the full scale community and air boats. Tip - All props have a failure point or service life. When a carbon prop is at that point it will begin to de-lam at the tip and make a different noise = replace.
