Half the contents on the PE frets I have purchased never get used. Mainly I use PE belts and the instrument panel/side consoles if and when it may be required. In 1:72 decal instruments look good, however for larger scales I usually run with the kit provided instrument panels unless they are pooly moulded.
I have just started to use resin bang seats and I am a convert, so from now on resin seats for modern aircraft and PE for WW2 seat harnesses.
The good thing is that Eduard have released the Zoom series to cater for those who just like to use the harnesses and minimum PE. Priced accordingly
Below is the Airwaves PE I used on my 1:48 Premiere BAe Hawk T.1A kit seats. They really dress the basic OOB seats nicely without having to source expensive resin replacements. The PE fret cost me AU$5 and added immensely to the scratchbuilding I did to the kit.
cheers
MikeJ