Well, so far nobody has mentioned my favorite whistle..... so I will now......

The Walton's (or Soodlums) mellow D.

I find they have a much sweeter sound then Generation (don't like them but play them when i need other keys.... ) but my fav is the mellow D. A little big bigger bore on the whistle give a nicer sound to my ear (and they tend to be a bit easier to play for beginners.)

I also play the Low D (Cheiftan), and yes, they are more difficult to play, not for a beginning player.... but beautiful when you get the hang of it..

musicman