Suits look sharper. Less cumberbund action getting in the way. No brainer. However, if someone can work a Gold Tux, possibly with Gold Top Hat, then that'd be snazzy [http://en.wikipedia.org/wiki/Moist_von_Lipwig].
My class got to have our prom in DoDDS [http://en.wikipedia.org/wiki/Heidelberg_Castle]-run American schools having quite big budgets.
The majority of us went suits.
In a castle.
http://i49.photobucket.com/albums/f277/baymoon_city/Things%20Unrelated%20to%20Work/SomeoneElsesPicOfHeidelbergCastle.jpg