I bought a 400F from my neighbor. It was a rescue, really. Sad life it led. Still, I resurrected it to run pretty darn well. I had been riding CB550s for a good long while.
The 400F scared the cr@p out of me. Wasn't very stable on it's own, and heavy breathing from sidewalk bystanders would nearly blow it over, or least cause an undesired lane change.
Engine power in a tight turn makes the front end even lighter and slide. Wear brown pants while riding this bike, or avoid engine RPMs above 4000-5000 and above.
You sit on this tiny pile of squirrely machine rather than into it. Your inner thighs need very strong muscles to keep the bike from squirting out from under you. Think about the bull riding machines, only one third the width and more bucking power. So, unless you have thigh muscles like Xenia Zaragevna Onatopp, don't expect to ever be "as one" with this machine.
You can't hang on the the bars either, as any side forces make you apply pressure to the bars in a way that accentuates those side forces. Basically, the machine takes a general clue from the rider and goes where it wants, and if you don't like it, too bad.
I sold mine a week after making it work again. She wouldn't sell it back later.
Cheers,
