Can't speak for models beyond '04 but.....
Lights: good enough, especially on brights (ran those most of the time)
Seat: good for me for around 400 miles
Fuel: well, that all depends on how much fun you're having and what you're definition of fun is. Heavy on the throttle? Out on the road I seem to recall getting 120 to 130 to a tank. In town and having fun? Maybe 95 miles to a thank. It's a bit thirsty, but you won't care.
As I said before, riding my Speed Triple was simply, and hands down, the most fun I've ever had on two wheels (with the possible exception of riding around the outside of jackasses on R1s on my VFR400). It's the best street bike I've ever owned.