My experience is with the current production KTS-4 that employs
Bone for both the Nut and Saddle.
Apparently, like yourself, I've been going around the "
decision rotisserie" of which new Kiwaya to purchase the last several weeks. I've picked the brains of those who own or owned KTS-4, KTS-5, KTS-6 and KTS-7 models, and I am very thankful for all the time from those who took the time to give their feedback and opinions.
I then sought out some local folks whom I met at Uke get togethers that own Kiwayas and thanks to them I was able to do some hands-on playing which, of course, was far more impactive and informative than listening to instruments over the Internet or solely relying on videos and owner's descriptions by themselves.
One the of the considerations that weighed heavily in my choice was if I wanted/needed the fretboard to go beyond 12-frets and came to the conclusion that it is not necessary in most, if not all, of music I play or practice with. I also didn't find much difference at all how better or worse the KTS-4 sounded to the others I played. I honestly felt the KTS-4 was on par, if not better sounding and feeling to me than the others. There was also something about the simplicity of the KTS-4. That's not to say that I don't like the KTS-7's style 3 look, after all, I did purchase a Martin Style 3 Cherry that has both a look, feel and sound that appealed to me greatly.
In the end, it came down to deciding between a new KTS-4 or a new KTS-7. While my budget allowed for either one, the tonal differences weren't there to say spending more would have given me a better sounding Uke than that of the KTS-4. I was also cognizant of the fact that the KTS-7 is built with Honduran Mahogany vs. the KTS-4 being built with African Mahogany as some were making a case for the Honduran species, while others expressed to me that they felt that a lot of it's appeal is becuase the Honduran species is more limited in availability than actually providing a superior tone. I'll leave that debate to those who study those things closer than I do, but the KTS-4's
non-Honduran mahogany sounds excellent to my ears.
So, with the comparison process completed, I chose to go with the instrument that really appealed to me the most overall, and that was the KTS-4. I guess it's partially why I may have an affinity for vintage S-0's, despite that KTS-4 has it's own sound. Of course if money were no object, the best solution would be to just get one of each...
.
The last local KTS-4 I was able to play was already spoken for, as the owner put it "will not be for sale", so I had to order one online. With the noted consistency Kiwaya has been praised for, I'm not at all put off by ordering one.
Looking forward to hear what you decide in your purchase journey...