Let me chip in my first impression.
A little background,
ZF1 3U>ZF1 4U>NR900 3U(Brief moment)>DZS 3U>N9II(T.A version) /TC75EX
Preference zf1 4u and N9ii TA version.
I believe when I said N9ii with soft/med shaft and fast frame and easily access to power, most existing user would agree.
100ZZ 4U, solid feel. Dry racket BP is similar to DZS 3U. Dry swing, fast and not too stiff compared to DZS. Gave me ZF1 4U feeling. Had my N9ii next to me before I purchase (sadly cracked during restringing due to years of abuse), and I can tell at least u can still bend 100ZZ a tad better though not on N9ii stiffness but definitely not as stiff as dzs or zf1.
Setup: Overgrip with original grip. Bg80 28lbs 4
knots.
This racket have the characteristics of HH, there's some weight in the head but the racket gave me a even balance feeling.
Just FYI, from here onwards most comparison relatively to N9ii and today is my first attempt (2 hour session) .
Warm up time, faster than my N9ii(2 years+ user) probably due to totally different specs and occasionally hitting frame with 100zz. But man when u hit it right, the accuracy and power is there(who am I kidding ) .
Lob/attack lob would need to exert slightly more energy but accuracy remain. Probably because N9ii 3u vs 100zz 4u but no complain there.
Overhead smash, pinpoint steep smash, but rear court power smash, I'm still unable to get steep angle. Half/mid court smash, steep and power and sound.
The smashing sound surprised me frankly speaking(definitely not dead tone compared to nr900)
Defensive wise, I believe this is where it gets better, for me at least(I'm a weak defensive player). Maybe due to shaft, maybe due to handle, I couldn't tell yet but it made my defensive shot more aggressive, turning from defensive receiving smash stance and drive it to where I want, easier. I would need more hours in this part but today I definitely i felt I have the upper hand.
Net play and drive, need to readjust a little on timing but its easier to guide the shuttle. Definitely fast enough with a little more power and accuracy.
Dropshot seems better than N9ii from accuracy wise, sharper and easier to control Dropshot speed.
Sore shoulder muscle. I tend to do countless power smash at the end of the day with a sparring partner but I never had it when using N9ii/75ex.
Conclusion, even with slight head weight, a 4u is still a 4u compared to my N9ii 3u. Would need more energy to execute comparable shot, coupled with stiffer shaft hence sore shoulder.
I'm keeping this. More forgiving than DZS on mishit.
Edit: add extra info. Also, forget to mention I'm using 100zz 4u, better to be on safe side