Awesome, dude. Thanks for sharing. Better also post it in the "Li Ning rackets fan club " thread, so more people will know.
That thread should be locked. While it's been good watching it grow over the years, it has now grown wayyy too long to be able to find any useful info from it in a reasonable amount of time.
For me personally (play every day 1hr with mavis 350 doubles), N90IV is very slow in defense in doubles since its head heavy. N9II more feels like astrox 88d to some extent more suitable for my doubles play. defense is far quicker with my N9ii than N90IV. - this is my personal opinion. Also i notice that flexible rackets like N9II, Arcsaber Z slash, astrox 88..etc perform better with plastic shuttle as plastic shuttles are lighter compared to feather, and the extra flex helps in generating more power. Stiffer rackets like N90IV perform better with feather shuttles which carry bit weight on them.