I have the first gen Li Ning N77 and I must say, it is very head light, a bit too head light for my liking. I haven't used it much but it is a good racket, power and repulsion are all there.
I'd put the flexibility at around stiff. The nanospeed 9900 is stiffer than it when used as a guideline. I also measured the balance point for you with a li ning overgrip and NBG 95 strings. Its at 280mm from the handle. The nanospeed on the other hand is 285mm. Hope that helps.