I used it on all my Fett stuff...HOWEVER it was not the final stage of my paintjob....In my opinion it makes the peice look 2-dimensional if it is the last thing done. The layers on Fett are what give it the 3-dimensional look so I use the "Dullcote",but still do my washes and some final weathering after using it. It also helps to shoot some Dullcote on during painting in stages if you're going to mask so as nothing will peel on you when lifting the masking.
Steve