Everyone has their views.Me personally be running around 250Bhp at flywheel with my fifth injector.Ive had no problem with mfi.Ford never built them to run stupid amounts of fuel.Hence the oldskol Fifth.efi is great,but then so many people do it.I try not to follow the crowd,go down my own route.For the worse or better.You cant floor the efi,its a good system.But some of us like taking the risk.If your after safe and money saving on fuel,plus around 17 to 20Bhp more than mfi,go efi.