Yea the lightness of the 650 is key. My commute shouldn't be too traffic heavy, but you never know.
FZ07 sounds alright but it's basically a modern version of my 650. If I went that route I'd prob jump to the FZ09, or the Street Triple.
I'm not crazy about the F4i. Prob scratch the ZX6R off too. I feel like they will be weak on the low end, which is kind of where I would like more power as that's where I do most of my ridiing.