I've got a 749R 04 also.
From all accounts the 57mm Termi gives better horsepower than the Leo Vinci.
As to looks, they don't really bother me and we stock both!!!
Depends what your looking for
Dunno if the Vinci comes with filters etc.
I would go with Termi and get a powercommander! (worked for me!!)
Martin
[Edited on 8-11-2005 by Martin Ducati Glasgow]