Is there something in csf / lfd that may cause occasional timeouts for visitors? I'm getting a few good complaints about that and not sure how to trace this as I'm not provided any info on clients end to trace the problem
I would recomend disabling it. I have seen nothing be issue with servers I have seen it on. All of those boxes where Cpanel boxes. I use APF without much issue myself but you do have to confiure it from the command line.