Your compression settings for the images will make the biggest difference in overall size (simiilar to resolution). We've sometimes saved things without compression at all and less downsizing. These files are very big. If we save the same thing with the same downsizing, but allow the compression to be JPEG maximum quality, the file could be MUCH smaller.

Does anyone know if there is a way to see exactly what resolution or compression settings were used when exporting from within Acrobat Pro? Preflight is a little too vague to show this info. You would think this info would be stored with the file.