Thanks to all who responded.
I have a total of 5 of the 500W PIR jobs to replace. I'll start by replacing one with a 26W smartflood with photocell and see how that goes.
Steve
I currently have a crop of 500W lights with individual PIR control providing 'security' lighting around my home.
I'm becoming convinced that having low wattage lights controlled by a photocell (dusk to dawn) might be superior.
The 500W lights are under the eves of a normal 2 story house...