Semisymetrical blades are a bit more efficient making lift but some react baddly when hovering in gusty conditions , and very tricky in aerobatics. Semis are not friendly to axial rolls.
I flew FAI semis for a year, not going back to them.
I found less efficient blades with shallow lift to angle of attack slope being best specially in gusty conditions. Best blades are between 220 and 235gm in weight, popular examples are the Radix FAI 710 and Rotortech FAI 720mm. There are other from Funtech and Hi-Products but hard to find.
My advice, stay away from semis for F3C