Easy to get the clear high and low notes

The high notes are rather difficult to sound clearly (without squeaking)

The notes are much clearer and it's has a beautiful shape

The higher notes aren't the smoothest, but a great whistle to learn with.

And on the Clarke when I don't squeak, I often don't get the correct sound / note

They both sound about the same but as a beginner I have found the Clarke much difficult to play the correct notes and have tended to squeak on the lower three notes (D, E, and F#) and the upper octave.

The notes sound very clear

Difficult to hit higher notes clean, but that requires practice.