I've been using TileMill recently and their focus is mainly web/html. The static maps (PNGs) are pretty, but there is also some frustrating aspects. For example

I've been using TileMill recently and their focus is mainly web/html. The static maps (PNGs) are pretty, but there is also some frustrating aspects. For example, PNG/PDF exports don't include legends and they don't have plans to implement that feature presently.