Balloons are a unique creative item which can be used for festive purposes, or can be used for formal events  such as weddings etc.  The difference is quality of balloons, color selections consistancy in the sizing of the balloons and how they are used in the overall decorating conceptual design.  Balloons have the unique quality of supporting tulle gossamer or other light fabric and having the fabric draping down to other sectors of a venue.
Balloon decor can be classy and elegant or cheesy and unattractive depending upon all of these factors.  What do you think?