We had a Gyro Trac GT 25 for several years, which is basically the same head design as the cimaf. We now have Fecon heads on CTL's and occasionally run Samurai teeth.
Trying to take into account the HP difference, I estimate that the two teeth would perform very similar on the same machine.
The fecon teeth are reversible. The cimaf teeth are much longer, meaning longer life. So with both sides of the fecon teeth, tooth life is probably comparable. However, if you hit something, the cimaf tooth is done, while you could turn the fecon tooth around.
The cimaf teeth are easier to sharpen since they are flat, the samurai teeth come to somewhat of a point.
Cimaf heads cost more.
If you are in rock free terrain and plan on running only knives, cimaf is hard to beat. If you don't plan on running knives all the time, go with fecon. Leave the carbides on, and put 10 knives in the middle when needed. Fecon also has a DCR rotor now, which has the depth control fins similar to cimaf.