I gave up on Dullcote spray bombs for a different reason. Try as I might, I can't get an even flat finish from it. Maybe it's my technique, but the flatness varies noticeably depending on whether there is some kind of raised detail or edge nearby. I don't have this problem with other flat finishes.
It's not flat, but I use ModelMasters semi-gloss for things like clean passenger cars that I want to seem "glossy" (cause a full-on gloss is just too much for me).