How is the Kelpie on high B and C#? Does it take a lot of extra push to play them clean without a tendency to drop back to the first octave? I’m thinking of getting one of these (Can’t afford the Pro) and I’d be interested to know how it plays at high A and above.
To add a point to the thread, I’ve found the Dixon two-piece polymer (conical) to be the easiest low D whistle for playing in the upper 2nd octave and beyond. I don’t experience the flatness that some complain of. The tone of the Dixon isn’t my favorite, which is why I’m always looking at other low Ds, but the high notes speak very easily (as they do on Dixon trad high D whistles, as well).
Even though they are popular and excellent whistles, I’ve was told MKs are not great when it comes to the upper second octave. They play flat above A apparently. Whether this applies to the Kelpie, I don’t know.
I totally agree with you regarding the tapered Dixon Low D. Equally I’m not so fond of the tone. Apparently Susato play quite reasonably up high. See the fifth posting at https://forums.chiffandfipple.com/t/low-ds-mk-burke-reviol-susato/66462/5
Another possibility though more expensive than the Kelpie at £145 inc shipping might be Lofgren. Marc Lofgren makes his Overton-like low whistles to order and is perfectly willing to shorten the window length slightly to make the whistle more relaxed in the upper second octave. That was a possibility I was considering myself . . . but now I have the Eyer.