Guy got next to me on the highway today and he was on a F3. He gave me "The Nod" and starting speeding up. We raced and I left him pretty bad. Are the F4 really that much faster?

There is a substanial difference, not just in peak power but in throttle response also. the F4i ( as you know) has fuel injection and it makes the power a bit smoother. and stronger, plus maybe he has carb issues thru the midrange??