The same rules for interior paint usually apply for exterior paints. The higher the sheen the more durable and capable of being washed. Other considerations for the sheen level are what item you are painting. If you are painting a large wall that isn't a focal point of the house you may want to consider a flat finish. Flat paint will hide better than satin paint. All of the potential spray marks and roller marks are less likely to be seen when you use flat paint. With that said, it shouldn't matter which sheen you use on the siding (if you apply the appropriate amount and back roll it, the finish should be even.)
Generally speaking you will want to use a higher sheen level on items that you want to stand out. Front doors, decorative trim boards, panneled ceilings etc are all good candidates for a satin or semi-gloss finish. Large walls typically go well with flat paint.
Above all is making sure you applying enough paint. You should apply two full coats. That means that the 2nd coat of acrylic paint should be applied 4 hours or so after the first coat (or at least move the ladder to every locatin twice). Lots of painters try and do a quick coat for the 2nd coat (that means that they wait for the first coat to set up for 5 minutes without moving their ladder and then quickly spray in the same place). It is not possible to do that with satin paint and shouldn't be done with flat paint either. Stick with quality paints, make sure you apply a full 2nd coat and use the higher sheens on items that you want to stand out.
Nick D
651-336-0561
