Yes, I was comparing between 3u VTZF and W3 N90 (1st gen), and both were strung with BG66UM @ 25lbs (2-knots). I guess the VTZF has a slightly stiffer shaft which makes it a little bit harder to generate the catapult effect, unless you have a very strong and explosive stroke. Again, others may feel differently.
I have tried smashing with the 3U and 4U versions of the ZForce, and there is a VERY BIG DIFFERENCE between them. Seems that the smashes done by N90 is similar to the 4U version
Sure, because vtzf is head-heavier than N90. Distributed Weight has been pushed more at 2' and 10' position, this leads to if you hold vtzf a bit higher to the cone, you feel it lighter. N90 weight is distributed evenly over the racket and less head-heavy comparing to vtfz, which give you a bit less powerful smash but more stable. N90 mostly is for singles, vtfz could be for both singles and double because if I hold it higher than normal position, I don't feel it heavy and the racket moves pretty fast.