4F is basically event horizon for bad netplay. If you can keep it at a solid 4F then it will be bearable. Don't use wireless connections, don't torrent, don't youtube, don't netflix etc. If any of that is going on, you aren't going to have a stable connection due to self inflicted packet loss. It is worth directly connecting your PS3/4 to your modem circumventing bad hardware inbetween if you are having issue. 5F+ is bad and not worth messing with. This is the same for basically any FG that you dial in the frame delay for netplay on the PC. Most people use 4F unless you know explicitly that somebody can round trip with you in less than 54ms(13.3_ x 4)
1-3f are nice assuming you aren't experiencing packet loss.