FWIW, Here's a pic of my bike.
One other thing I've noticed is that there are far more options on aftermarket parts for the 750 than there are the 550.
Take exhausts for instance. The ugly POS on mine is a Mac. There are three different Macs to choose from for the 550: black, black with chrome canister, chrome megaphone. Then Sito has a slip on system that uses the stock headers. Benjie has beautiful pipes for the 550, but they're pricey. And, everyone else correct me if I'm wrong, but I think that's it for options.
There are waaaayyyy more exhaust options for the 750. Just something else to keep in mind.
Jeff