My favorite whistles right now are my new Ralph Sweet D and my Susato C. I wish I had a Sweet C and a Susato D...The Sweet is very mellow and (dare I say it) sweet. The Susato is clear and loud. Both are tunable and reliable in both octaves.

I have a Susato G and Low D, both of which I'm still learning to play better. They too are clear, loud, and reliable.

I also have Clarke Sweetones, Generations, an Oak and a Feadog, none of which I enjoy playing like the Sweet and Susatos. They all have more "chiff" and tonal variations, and inconsistencies between octaves. I don't know if that's cause I can't play them right, or whether they are flawed, but the Sweet and Susato whistles make me sound like I know what I'm doing AND I can afford them.

fwiw, my $0.02. Your mileage may vary!

V