what are you looking for in the new bike besides being smooth and quiet? Do you need something more powerful than the versys? Or are you looking for something to tool around town on like you stole it?
F4i would be good for a slight power upgrade from the Versys, the ZZR too but it has carbs (dont know if that is an issue). If you are looking for more power any 600 cc sport bike pre 2006 with a stock exhaust. If you want mid range grunt check out the 919 or z1000.
Now if you want a bike that you can push to its limits on city streets and can handle almost as well as sport bikes check out klx250sf (19 rwHP), wr250x (25 rwHP), CBR250 (25 crank HP).
I am going to be adding a 2011 TU250x this year to my stable just for that reason. I am guessing this is not your style tho, but my plan is to ride it around town like i stole it.