Well, Grn, I have much the same experience as you. Handling, stability, smoothness, comfort, and power (of course) are as you say they are and all there with nearly instant access (torque monster) and in abundant supply. It also brakes like a champ, especially with engine braking combined with the slipper clutch to keep things smooth and direct. Love it!
However, I do have some clunkiness at times going into first from neutral; usually this occurs when bike is pointed up a hill or rise. Why that correlation, IDK? Now it isn't as bad as the old gen 1 and it isn't always present; it is mostly a sound without a vibration through the bike. So, it is reduced at best with the new R, but still present under certain conditions without being overly intrusive. It is not enough to cause me to flinch, as the bike would "buck" under the same action on the old ZX.
Yes, it "power shifts", under acceleration without clutch use, like a dream! I have never ridden another bike that could do this so easily and smoothly. I find it actually preferable to using the clutch for all brisk acceleration applications, not just on the occasions that I am "channeling" RG.
Having said that, I have had one instance of unexplainable 'clatter' during a normal clutched shift. IDK if it was from the clutch or tranny. At first I thought I had missed the shift and the tranny was in a false neutral with the gears bouncing about on their shafts, but thankfully there was no physical vibration or jerkiness in the drive train. It was as though I had a broken connection to the rear sprocket. I pulled in the clutch and toe'd up hard on the shifter peg to be sure I was in gear; it was pretty solidly seated and when I let the clutch back out, all was good.
No apparent foul or harm, so perhaps it was something going on with the slipper function of the clutch? Clatter coming from clutch and not the tranny? IDK, but I pushed the bike hard for several miles with some full acceleration and no problems.
Another big difference from my old ZX14 is the power delivery in the upper rpm range. There is no "beast" that awakens at about 9k rpm any more! At first I found this to be disappointing since I had anticipated a sudden rush even over what was being generated at lower rpm. Then I realized that the "beast" had simply come on sooner and more linearly from about 7k on up! My runways have been seemingly shortened on my favorite stretches due to this phenomena and the bike just pulls and pulls forever without a drama zone! Yesssssssss, the full 'warp factor' acceleration is still there and more so; but, the power is more evenly distributed over a larger range of rpm.
There is a bit of hesitation in extreme low rpm; (below 3k rpm for sure )and I expect removing flies or doing an ecu flash might remedy that and move the bike into the 5k rpm bigger power mode expeditiously. I personally don't find it a major problem as it was on the old bike. I just keep it above that low rpm range and, if just starting out from a stop, let the slipper clutch help me start at a more elevated rpm point. I can see where a dedicated 'hot shoe' or stop light to stop light racer would want to "fix' this. For me it is not an issue needing rectification.
I am just beginning to spend more time in the 7 to 11k rpm range and expect to do so regularly over the next 500 miles or so, followed by a change to full synthetic oil from the dino oil currently in the pan since 650 miles change. Then will run Amsoil synthetic as standard fare for the life of the bike. I expect the synthetic will smooth the gear changes even more as it did for the old bike.
This thing is the NUTS!
Nothing is more responsible for the good old days than a bad memory. (Franklin Pierce Adams)