I had the chance to do a pretty thorough comparison of my "old" YAS-82z and the new "ii" version. The V1 neck was in use on both horns. Looks: It can be hard to tell the new one from the old on first sight. The designation "ii" is not engraved anywhere on the horn that I could find. Instead look for the metal resonators and adjustable front F doo-dad. The new engraving isn't that different from previously though, as Yamaha says, the engraving is indeed "finer". A smaller (finer) nib is used and the some of patterns are more delicate. But the design is not more elaborate IMO. The old horn looked very pretty so does the new one. The excellent Custom case is still the same shape but is updated with heavier latches and a more leather-like outer material. Now to the important stuff.... Action: Simply put, the action is smoother! The keys are much less noisy and are in general smoother in action. The low C# was a particular problem for me on the old horn. It basically 'bounced' open and I felt that coming through the horn. It almost felt like I bumped into something when I pressed that key. On the new horn it's quite and accurate. Yamaha makes a point of the new C# - B design on the cluster and yes, it's a little easier to play, but I didn't really have a problem with that move on the old horn. My new Z is a little stiff out of the box but I really enjoy the quieter, smoother feel. (Maybe it's me that's a little stiff out of the box? ...). Tone: Overall the sound is a little darker. It's not really dark, like some Mark VI's (I have one of those too), but more in that direction. You do get more fundamentals in the sound throughout the range. Another way of putting it is the sound is less "nasal", or is more "throaty". This is especially notable on the low tones, and this may be related to the new single piece bell modification Yamaha highlights (though I think the low notes and the older model were certainly acceptable sounding). The main thing is that you still get the same great projection with this horn, even if it is a tad more polite about it. Intonation: Seems better for me. I always struggled a bit with open C# on the old Z and I feel that this is not happening on the new horn, however I'd like to play it more and in more situations before I say for sure. Note that plenty of players did NOT have any intonation issues with the old Z. I'll try to remember to update the playing in tune thing one of these days .... I'd rap it up by saying the new Z is a lot like the old one, 90% the same feel, but more mature or smoothed out. The older model is perhaps a bit "idiosyncratic". I can imagine you would not want to make the switch if A) you have no issue with the action or intonation on your current Z and/or B) you like the brighter sound of the old Z. I wouldn't consider making the switch without comparing the saxes side by side. As for me, the smoother action and the richer tone were enough to make the switch.