In stock form, they're pretty gutless under 7000rpm.
A friend of mine has amodded gen 2 FZ1. It has balls. Power wise, if felt to me, as strong as my 929. He does not agree, he says the 929 is noticibly stronger. So power wise, it is at least in the same ballpark, which is very good. However, to get it to run as it does, it had the kitchen sink thrown at it. It has the airbox cut, different air filter,a PowerCommander, an Ivan's FCE, cat removed, slip on, and I think a smaller front sprocket, and a speedo healer. And all of that is ok. Most of us end up doing most of that to any bike we own anyways. But an FZ HAS to have it done. My WR450 was pretty much the same way.
Handling wise, it's still an FZ. The gen 1s were a barge. The gen 2 aren't a whole lot better. A well set up 919 will leave em in the corners, but get murdered in the open.