Ok I think I finally found the issue. I do see the difference now. I did some more testing on your site and could also see how the font looks different. It was hard as I'm not used to the language and characters used.
So some reason Content King is using Sans Serif even though Exo is selected and listed first in the on font list as you can see below. I believe the following should fix this. Open up the index.php file for Content King and look for:
body, .inputbox {font-family: '<?php echo $s5_fonts;?>',Helvetica,Arial,Sans-Serif ;}
change it to:
body, .inputbox {font-family: '<?php echo $s5_fonts;?>' ;}