It's totally different from both of those. I mainly use the NR750 now so I can compare it with that. NRZ is very heavy in the head and takes a lot more effort to swing. Just like Mark said, if you don't get it in that sweet spot the shot pretty much goes no where. Defense is horrible for me compared to any of the other rackets I've used. The NR750 and the NRZ are very different from each other. I'm sticking with the NR750.
Personally for me, I liked the 750 more. The 800 was too stiff and headlight. The 750 has an even balanced feel with a little weight towards the head. Very easy to swing and generate power with it.
I want a racket that is head light as my BS12 but stiffer. I guess this is not the racket. Should I buy NS9900?
NR800 would be my first stop - the NS9900 is a very uncompromising racket: very headlight and very stiff.
Have you tried the BS10 or 11? As said the NS9900 is much stiffer but has a more dampened feel compared to the BSs. If you want to keep the speed you get with the BS frames, try BS10 - which is faster than BS12.
I have both the BS12 (2U Korean National Team edition) and the NS9900 (2U). The BS12 is better in defense and slightly better at the net but it lacks of the power of the NS9900. Also in my opinion, the NS9900 is rather balance than very head light. I still prefer the NS9900 only 2U version. 3U is too light for me and I can't generate enough power with it. But that's my personal opinion only.
I just completed 8 hours of playing with my Z Speed 3u strung at 23lbs with Zymax 65, my notes would be as follows: Great paint job - vibrant!! I felt my VT80 swings faster than the Zspeed when testing it on drive shots It's not great at changing direction in doubles or quick enough to defend against big smashes. Clears back hand or forehand are easy enough Drop shots are accurate Control is average overall though Smashes are very good, better than the ZF for me In conclusions I found it better to play singles with but not quick enough to play a reasonably quick (intermediate/advanced) doubles game with. The points gained through heavy smashes are equaled through the points lost from poor defence (millisecond differences count here) or reaction times. It is however one of the easiest Z's to just pick up and play with, ultimately for me, the VT80 is the pick of the Yonex range and still the better all round racket. Jag
After playing 4 hours with the Z Speed I can say it feels very similar to my Voltric 70 I usually play with.
What's everyone's opinion on the best string of choice for this racquet? I've tried NBG95 @ 26 lbs and enjoyed it. But I'm currently using BG70 @ 26 lbs and I'm rather unimpressed or confused with his performance. Very little feedback on this string.. I know it's probably personal preferences but any suggestions will do. I've considered ZM65, ZM67, BG80, possibly even ZM62 / BG66UM