I recently took up whistling, after a Feadog and Clarke Sop d's I bought a Dixon tuneable A - fantastic sound, I cant put it down. The upper octave is very sweet, not shrill like most Sop D whistles. The lower Octave is warm and great for legato playing. Im going to order a tuneable G next. I'll probably also get the more expensive brass slide tuneable polymer C & D Sop whistles. I was less impressed with the Dixon Low D's, great for the money but I find the plastic models a bit too soft when you're going down that low, but now Tony's brought out an Aluminium bodied range theres a good chance I'll like the Low D version!