I have been playing all types of whistles for a long time but never a low D whistle, so i done some research and came across the Chieftain custom low d, so i took a chance and ordered one, 
Pros- beautiful looking, nice weight, and a superb deep sound, 
the holes are closer together so making it easy to handle 
Cons- price was more than i ever paid for a whistle but worth every penny,