Monroville said:
I think that's my biggest gripe is that they are merely dots on the horizon when it would be nice to tell that they are star destroyers (yes, Han tells me that, but I'd like to see them)

In this case, though, if they were clearly visible, it would become a 'master of the obvious' moment. If they're just dots (and the passengers are thinking 'what is that?'), then Han is looking at the instruments and telling his passengers 'star destroyers ahead.' If everyone could see them, it would be like 'no kidding, Han...'