I’ve been struggling with the higher notes (A and above) on my Susato and Dixon Trad D whistles. This morning I had the house to myself, so I figured nobody would care if I got out the Clarke Original I could never play. I worked on several tunes until the high notes came out clearly on the Clarke. Then I picked up first the Susato, then the Dixon. Wow. I can play clearly all the way up to high D. It’s like my mouth and throat and tongue finally figured out where to be for the high notes to sound (kind of like when I was learning to play flute). I’m so pleased!! The extra resistance of the Clarke must have given me the push I needed.
i find it so helpful to play a number of different whistles (or any instrument, really)
many times you can fight the instrument due to quality or just it’s own characteristic, and get frustrated; when trying another instrument can be fresh and get you where you need to go, even back to the original instrument that caused the frustration!
When you say high D, do you mean the 2nd or 3rd D? If you’re talking about the 2nd D then you’d really want to be able to go way above that to at least high B, assuming you’re playing Irish trad?
The more I play the little Clarke, the more I like it. The one I like the least is the Susato. It is easier to play, but harder on my ears. Maybe I’m developing a taste for chiff?
Congratulations. Isn’t that a nice feeling? I was able to play in public this weekend a song that just hangs out in the high notes and I played it nicely and smoothly. The last time I tried this song, the other folks suggested another instrument.
It seems to me that with every new technology there is much gained and something lost. For example, electric lights are much brighter than oil lamps–but you lose that soft yellow glow. I am mourning the decline of writing with paper and ink, and receiving a hand-written letter from a friend. And, with the Clarke, that soft, whispery sound is something that is lost on the more efficient whistles.
In answer to the question, what whistle do you like best, I once came up with the answer: the one I’ve been playing for the past five minutes.
By which I meant that within a short time you can get used to get how any whistle* sounds, find out how to make it work and enjoy playing it. Pick up a Clarke when you haven’t been near one for ages… wow, it’s different. Keep playing it for a while… wow it’s great. A point may even come when you think the same way about a Susato.
It’s like my mouth and throat and tongue finally figured out where to be for the high notes to sound (kind of like when I was learning to play flute). I’m so pleased!! 
The extra resistance of the Clarke must have given me the push I needed.