I am a competitive F-Class shooter and the SFP is king. I am sure there are a few competitors that use FFP but I don't know any personally.
There is really no reason to use a FFP at known distances. I will admit though we luck out because target pullers give us instant feedback or even better we shoot electronic targets. I have tried a FFP in a mid range practice and found it covered the 1-1/2" spotting disc which sometimes is my aim point in heavy mirage.

As for field work I mainly shoot antelope at fair distances and always use SFP. I can range with the reticle for this purpose or use a laser range finder.

I can see the need for FFP in PRS and it fits the bill for that purpose. I have shot teamed AR/PR matches with my antelope rifle and done fairly well with a SFP. The AR we were using used a FFP. Having to range and shoot multiple targets in a set time limit I saw the benefit. Especially movers.

I guess it comes down to the game you shoot and what you find comfortable behind.